Okta (OKTA) 10-K 14 Mar 19 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Jan. 31, 2019	Feb. 28, 2019	Jul. 31, 2018
Entity Information [Line Items]
Document Type	10-K
Document Period End Date	Jan. 31, 2019
Amendment Flag	false
Entity Registrant Name	Okta, Inc.
Entity Central Index Key	0001660134
Current Fiscal Year End Date	--01-31
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2019
Document Period Focus	FY
Entity Well-Known Seasoned Issuer	Yes
Smaller Reporting Company	false
Emerging Growth Company	false
Shell Company	false
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 4.7
Class A Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		101,267,377
Class B Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		10,957,938

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Jan. 31, 2019	Jan. 31, 2018	[1]
Current assets:
Cash and cash equivalents		$ 298,394	$ 127,949	[2]
Short-term investments		265,374	101,765
Accounts receivable, net of allowances of $2,098 and $1,472		91,926	52,248
Deferred commissions		24,185	17,755
Prepaid expenses and other current assets		29,451	17,781
Total current assets		709,330	317,498
Property and equipment, net		52,921	12,540
Deferred commissions, noncurrent		54,812	40,755
Intangible assets, net		13,897	11,761
Goodwill		18,089	6,282
Other assets		15,286	10,427
Total assets		864,335	399,263
Current liabilities:
Accounts payable		17,212	9,566
Accrued expenses and other current liabilities		9,959	6,187
Accrued compensation		19,770	12,374
Convertible senior notes, net		271,628	0
Deferred revenue		245,622	159,816
Total current liabilities		564,191	187,943
Deferred revenue, noncurrent		8,768	4,963
Other liabilities, noncurrent		38,999	7,017
Total liabilities		611,958	199,923
Commitments and contingencies (Note 10)
Stockholders’ equity:
Preferred stock, par value $0.0001 per share; 100,000 shares authorized, no shares issued and outstanding as of January 31, 2019 and 2018.		0	0
Additional paid-in capital		744,896	565,653
Accumulated other comprehensive income (loss)		(319)	391
Accumulated deficit		(492,211)	(366,714)
Total stockholders’ equity	[3]	252,377	199,340
Total liabilities and stockholders’ equity		864,335	399,263
Class A Common Stock
Stockholders’ equity:
Common stock		10	7
Class B Common Stock
Stockholders’ equity:
Common stock		$ 1	$ 3
[1]	See Note 2 for a summary of adjustments.
[2]	See Note 2 for a summary of adjustments.
[3]	See Note 2 for a summary of adjustments. The cumulative effect adjustment to Accumulated Deficit and Total Stockholders' Equity (Deficit) related to the adoption of ASU No. 2014-09 (Topic 606) as of January 31, 2016 was $22.8 million.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Statement of Financial Position [Abstract]
Allowance for accounts receivable	$ 2,098	$ 1,472
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	100,000,000	100,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A Common Stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	101,093,322	70,610,000
Common stock, shares outstanding (in shares)	101,093,322	70,610,000
Class B Common Stock
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	120,000,000	120,000,000
Common stock, shares issued (in shares)	11,059,181	33,361,000
Common stock, shares outstanding (in shares)	11,059,181	33,361,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017	[1]
Revenue
Total revenue		$ 399,254	$ 256,547	[1]	$ 160,806
Cost of revenue
Total cost of revenue		113,421	80,755	[1]	55,949
Gross profit		285,833	175,792	[1]	104,857
Operating expenses
Research and development		102,385	70,821	[1]	38,659
Sales and marketing		227,960	165,020	[1]	110,769
General and administrative		75,110	51,803	[1]	30,099
Total operating expenses		405,455	287,644	[1]	179,527
Operating loss		(119,622)	(111,852)	[1]	(74,670)
Interest expense		(15,072)	0	[1]	0
Other income (expense), net		9,180	1,682	[1]	39
Loss before provision for (benefit from) income taxes		(125,514)	(110,170)	[1]	(74,631)
Provision for (benefit from) income taxes		(17)	(321)	[1]	425
Net loss	[2]	$ (125,497)	$ (109,849)	[1],[3],[4]	$ (75,056)	[3],[4]
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)		$ (1.17)	$ (1.32)		$ (3.94)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted (in shares)		107,504	83,004	[1]	19,038
Subscription
Revenue
Total revenue		$ 370,855	$ 236,422	[1]	$ 144,909
Cost of revenue
Total cost of revenue		77,354	52,481	[1]	34,211
Professional services and other
Revenue
Total revenue		28,399	20,125	[1]	15,897
Cost of revenue
Total cost of revenue		$ 36,067	$ 28,274	[1]	$ 21,738
[1]	See Note 2 for a summary of adjustments.
[2]	See Note 2 for a summary of adjustments. The cumulative effect adjustment to Accumulated Deficit and Total Stockholders' Equity (Deficit) related to the adoption of ASU No. 2014-09 (Topic 606) as of January 31, 2016 was $22.8 million.
[3]	See Note 2 for a summary of adjustments.
[4]	See Note 2 for a summary of adjustments.

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands		12 Months Ended
		Jan. 31, 2019	Jan. 31, 2018	[3]	Jan. 31, 2017	[3]
Statement of Comprehensive Income [Abstract]
Net loss	[1]	$ (125,497)	$ (109,849)	[2],[4]	$ (75,056)	[2],[4]
Net change in unrealized gains (losses) on available-for-sale securities		179	(202)		10
Foreign currency translation adjustments		(889)	760		(120)
Other comprehensive income (loss)		(710)	558		(110)
Comprehensive loss		$ (126,207)	$ (109,291)		$ (75,166)
[1]	See Note 2 for a summary of adjustments. The cumulative effect adjustment to Accumulated Deficit and Total Stockholders' Equity (Deficit) related to the adoption of ASU No. 2014-09 (Topic 606) as of January 31, 2016 was $22.8 million.
[2]	See Note 2 for a summary of adjustments.
[3]	See Note 2 for a summary of adjustments.
[4]	See Note 2 for a summary of adjustments.

CONSOLIDATED STATEMENTS OF REDE

CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Total		Series B Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock	Common StockClass A Common Stock	Common StockClass B Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment | Accounting Standards Update 2014-09	$ 22,800								$ 22,800
Beginning balance (in shares) at Jan. 31, 2016	59,465,439
Beginning balance at Jan. 31, 2016	$ 227,954
Ending balance (in shares) at Jan. 31, 2017	59,465,439
Ending balance at Jan. 31, 2017	$ 227,954
Beginning balance (in shares) at Jan. 31, 2016					0	19,325,074
Beginning balance at Jan. 31, 2016	(158,271)	[1]			$ 0	$ 2	$ 23,393	$ (57)	(181,609)	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and other activity, net (in shares)						954,329
Issuance of common stock upon exercise of stock options and other activity, net	3,298	[1]					3,298
Issuance of common stock pursuant to charitable donation (in shares)						13,935
Issuance of common stock pursuant to charitable donation	129	[1],[2]					129
Stock-based compensation	17,649	[1]					17,649
Other comprehensive loss	(110)	[1]						(110)
Net loss	(75,056)	[1],[2],[3],[4]			$ 0	$ (75,056)			(75,056)	[1]
Ending balance (in shares) at Jan. 31, 2017					0	20,293,338
Ending balance at Jan. 31, 2017	(212,361)	[1]			$ 0	$ 2	44,469	(167)	(256,665)	[1]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment | Accounting Standards Update 2016-09	0	[1]					200		(200)	[1]
Issuance of redeemable convertible preferred stock (in shares)			26,201
Issuance of redeemable convertible preferred stock			$ 408
Conversion of convertible preferred stock to common stock in connection with initial public offering (in shares)				(59,491,640)		59,491,640
Conversion of convertible preferred stock to common stock in connection with initial public offering	$ 228,362	[1]		$ (228,362)		$ 6	228,356
Ending balance (in shares) at Jan. 31, 2018	0
Ending balance at Jan. 31, 2018	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and other activity, net (in shares)					8,274,599	900,517
Issuance of common stock upon exercise of stock options and other activity, net	34,698	[1]			$ 1		34,697
Issuance of common stock upon net exercise of warrant (in shares)						168,750
Issuance of common stock in connection with initial public offering, net of underwriting discounts and issuance costs (in shares)					12,650,000
Issuance of common stock in connection with initial public offering, net of underwriting discounts and issuance costs	194,345	[1]			$ 1		194,344
Conversion of convertible preferred stock to common stock in connection with initial public offering (in shares)				(59,491,640)		59,491,640
Conversion of convertible preferred stock to common stock in connection with initial public offering	228,362	[1]		$ (228,362)		$ 6	228,356
Issuance of common stock and restricted stock in connection with acquisition (in shares)						1,598,500
Issuance of common stock and restricted stock in connection with acquisition	3,652	[1]					3,652
Issuance of common stock pursuant to charitable donation (in shares)					24,287
Issuance of common stock pursuant to charitable donation	708	[1],[2]					708
Issuance of common stock under employee stock purchase plan (in shares)					569,373
Issuance of common stock under employee stock purchase plan	8,369	[1]					8,369
Conversion of Class B common stock to Class A common stock (in shares)					49,091,639	(49,091,639)
Conversion of Class B common stock to Class A common stock	0	[1]			$ 5	$ (5)
Stock-based compensation	50,858	[1]					50,858
Other comprehensive loss	558	[1]						558
Net loss	(109,849)	[1],[2],[3],[4]			$ (31,980)	$ (77,869)			(109,849)	[1]
Ending balance (in shares) at Jan. 31, 2018					70,609,898	33,361,106
Ending balance at Jan. 31, 2018	$ 199,340	[1],[5]			$ 7	$ 3	565,653	391	(366,714)	[1]
Ending balance (in shares) at Jan. 31, 2019	0
Ending balance at Jan. 31, 2019	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and other activity, net (in shares)	6,576,700				6,465,957	104,084
Issuance of common stock upon exercise of stock options and other activity, net	$ 37,611	[1]			$ 1		37,610
Issuance of common stock pursuant to charitable donation (in shares)					20,000
Issuance of common stock pursuant to charitable donation	1,008	[1]					1,008
Issuance of common stock under employee stock purchase plan (in shares)					615,210
Issuance of common stock under employee stock purchase plan	13,727	[1]					13,727
Issuance of common stock for settlement of RSUs (in shares)					976,248
Conversion of Class B common stock to Class A common stock (in shares)					22,406,009	(22,406,009)
Conversion of Class B common stock to Class A common stock	0	[1]			$ 2	$ (2)
Equity component of convertible senior notes, net of issuance costs	77,631	[1]					77,631
Issuance of warrants related to convertible notes	52,440	[1]					52,440
Purchase of convertible senior notes hedges	(80,040)	[1]					(80,040)
Stock-based compensation	76,867	[1]					76,867
Other comprehensive loss	(710)	[1]						(710)
Net loss	(125,497)	[1]			$ (107,926)	$ (17,571)			(125,497)	[1]
Ending balance (in shares) at Jan. 31, 2019					101,093,322	11,059,181
Ending balance at Jan. 31, 2019	$ 252,377	[1]			$ 10	$ 1	$ 744,896	$ (319)	$ (492,211)	[1]
[1]	See Note 2 for a summary of adjustments. The cumulative effect adjustment to Accumulated Deficit and Total Stockholders' Equity (Deficit) related to the adoption of ASU No. 2014-09 (Topic 606) as of January 31, 2016 was $22.8 million.
[2]	See Note 2 for a summary of adjustments.
[3]	See Note 2 for a summary of adjustments.
[4]	See Note 2 for a summary of adjustments.
[5]	See Note 2 for a summary of adjustments.

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		12 Months Ended
		Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017
Cash flows from operating activities:
Net loss	[1]	$ (125,497)	$ (109,849)	[2],[3],[4]	$ (75,056)	[2],[3],[4]
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock-based compensation		76,320	49,860	[4]	17,127	[4]
Depreciation, amortization and accretion		8,001	7,001	[4]	4,568	[4]
Amortization of debt discount and issuance costs		14,279	0	[4]	0	[4]
Amortization of deferred commissions		20,852	15,180	[4]	10,466	[4]
Deferred income taxes		(765)	(534)	[4]	0	[4]
Write-off of intangible assets		0	1,114	[4]	0	[4]
Non-cash charitable contributions		1,008	708	[4]	129	[4]
Other, net		640	719	[4]	575	[4]
Changes in operating assets and liabilities:
Accounts receivable		(39,682)	(18,321)	[4]	(11,993)	[4]
Deferred commissions		(41,342)	(26,986)	[4]	(24,096)	[4]
Prepaid expenses and other assets		(11,624)	(9,400)	[4]	(3,224)	[4]
Accounts payable		675	3,505	[4]	1,529	[4]
Accrued compensation		7,429	3,582	[4]	1,967	[4]
Accrued expenses and other liabilities		15,575	521	[4]	2,387	[4]
Deferred revenue		89,303	57,660	[4]	33,520	[4]
Net cash provided by (used in) operating activities		15,172	(25,240)	[4]	(42,101)	[4]
Cash flows from investing activities:
Capitalized internal-use software costs		(2,851)	(5,431)	[4]	(5,489)	[4]
Purchases of property and equipment		(19,811)	(6,550)	[4]	(6,253)	[4]
Proceeds from sales of property and equipment		740	0	[4]	0	[4]
Purchases of securities available for sale		(631,488)	(129,086)	[4]	0	[4]
Proceeds from maturities and redemption of securities available for sale		298,650	39,825	[4]	12,500	[4]
Proceeds from sales of securities available for sale		173,072	1,538	[4]	6,207	[4]
Payments for business acquisition		(15,632)	0	[4]	0	[4]
Net cash provided by (used in) investing activities		(197,320)	(99,704)	[4]	6,965	[4]
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriters' discounts and commissions		0	199,948	[4]	0	[4]
Proceeds from issuance of convertible senior notes, net of issuance costs		334,980	0	[4]	0	[4]
Purchase of convertible senior notes hedge		(80,040)	0	[4]	0	[4]
Proceeds from issuance of warrants related to convertible notes		52,440	0	[4]	0	[4]
Payments of deferred offering costs		0	(4,038)	[4]	(1,584)	[4]
Proceeds from exercise of stock options, net of repurchases and other		36,861	33,646	[4]	2,437	[4]
Proceeds from issuance of convertible redeemable preferred stock, net of issuance costs		0	8,369	[4]	0	[4]
Proceeds from shares issued in connection with employee stock purchase plan		13,727	0	[4]	0	[4]
Other, net		(206)	(517)	[4]	(396)	[4]
Net cash provided by financing activities		357,762	237,408	[4]	457	[4]
Effects of changes in foreign currency exchange rates on cash, cash equivalents and restricted cash		(632)	487	[4]	(120)	[4]
Net increase (decrease) in cash, cash equivalents and restricted cash		174,982	112,951	[4]	(34,799)	[4]
Cash, cash equivalents and restricted cash at beginning of year	[4]	136,233	23,282		58,081
Cash, cash equivalents and restricted cash at end of year		311,215	136,233	[4]	23,282	[4]
Cash paid during the period for:
Income taxes		514	747	[4]	0	[4]
Non-cash investing and financing activities:
Vesting of early exercised common stock options		763	1,335	[4]	1,297	[4]
Issuance of common stock in connection with warrant exercises		0	272	[4]	0	[4]
Common stock issued as charitable contribution	[1]	1,008	708	[4]	129	[4]
Assets acquired under financing arrangement		0	0	[4]	386	[4]
Deferred offering costs, accrued but not yet paid		0	0	[4]	2,106	[4]
Property and equipment acquired through tenant improvement allowances		22,236	0	[4]	1,332	[4]
Property and equipment and other accrued but not yet paid		7,225	111	[4]	1,367	[4]
Issuance of common stock in connection with business combination		0	2,160	[4]	0	[4]
Conversion of redeemable convertible preferred stock to common stock		0	228,362	[4]	0	[4]
Reconciliation of cash, cash equivalents, and restricted cash within the consolidated balance sheets to the amounts shown in the statements of cash flows above:
Total cash, cash equivalents and restricted cash	[4]	$ 136,233	$ 23,282		$ 58,081
[1]	See Note 2 for a summary of adjustments. The cumulative effect adjustment to Accumulated Deficit and Total Stockholders' Equity (Deficit) related to the adoption of ASU No. 2014-09 (Topic 606) as of January 31, 2016 was $22.8 million.
[2]	See Note 2 for a summary of adjustments.
[3]	See Note 2 for a summary of adjustments.
[4]	See Note 2 for a summary of adjustments.

Overview and Basis of Presentat

Overview and Basis of Presentation	12 Months Ended
	Jan. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Overview and Basis of Presentation	Overview and Basis of Presentation Description of Business Okta, Inc. (the Company) is the leading identity management platform for the enterprise. The Okta Identity Cloud enables customers to securely connect people to technology, anywhere, anytime and from any device. The Company was incorporated in January 2009 as Saasure, Inc., a California corporation, and was later reincorporated in April 2010 under the name Okta, Inc. as a Delaware corporation. The Company is headquartered in San Francisco, California. Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements, which include the accounts of the Company and its wholly owned subsidiaries, have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). All intercompany balances and transactions have been eliminated in consolidation. Certain immaterial reclassifications of prior period amounts have been made in our consolidated balance sheets and consolidated statements of cash flows to conform to the current period presentation. The Company’s fiscal year ends on January 31. References to fiscal 2019 , for example, refer to the fiscal year ended January 31, 2019 . Initial Public Offering In April 2017, the Company completed an initial public offering (IPO), in which the Company issued and sold 12,650,000 shares of its newly authorized Class A common stock at a public offering price of $17.00 per share. The Company received aggregate proceeds of $200.0 million from the IPO, net of underwriters’ discounts and commissions, before deducting offering costs of approximately $5.6 million . Immediately prior to the completion of the IPO, all shares of common stock then outstanding were reclassified as Class B common stock, and all shares of redeemable convertible preferred stock then outstanding were converted into 59,491,640 shares of common stock on a one -to-one basis and then reclassified into Class B common stock. Convertible Senior Notes In February 2018, the Company issued $345.0 million aggregate principal amount of 0.25% convertible senior notes due February 15, 2023 in a private offering, including the initial purchasers’ exercise in full of their option to purchase additional notes (2023 Notes). The Company received aggregate proceeds of $345.0 million , before deducting costs of issuance of $10.0 million . See Note 9 for additional details. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates, judgments and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. The Company bases its estimates on historical experience and on other assumptions that its management believes are reasonable under the circumstances. Actual results could vary from those estimates. The Company’s most significant estimates include the stand alone selling price (SSP) for each distinct performance obligation included in customer contracts with multiple performance obligations, the determination of the period of benefit for deferred commissions, the determination of the effective interest rate of the liability components of the 2023 Notes, determination of the fair value of the Company’s common stock prior to the completion of the IPO, the valuation of deferred income tax assets and contingencies and the valuation of acquired intangible assets. Foreign Currency The functional currencies of the Company’s foreign subsidiaries are the respective local currencies. Translation adjustments arising from the use of differing exchange rates from period to period are included in accumulated other comprehensive loss within the consolidated statements of redeemable convertible preferred stock and stockholders’ equity (deficit). Foreign currency transaction gains and losses are included in other expense, net in the consolidated statements of operations and were not material for the years ended January 31, 2019 , 2018 or 2017 . All assets and liabilities denominated in a foreign currency are translated into U.S. dollars at the exchange rate on the balance sheet date. Revenue and expenses are translated at the average exchange rate during the period, and equity balances are translated using historical exchange rates.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Jan. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Segment Information The Company operates in a single operating segment. The Company’s chief operating decision maker is its chief executive officer, who reviews financial information presented on a consolidated basis for purposes of making operating decisions, assessing financial performance and allocating resources. Revenue Recognition The Company derives revenue from subscription fees (which include support fees) and professional services fees. The Company sells subscriptions to its platform through arrangements that are generally one to five years in length. The Company’s arrangements are generally noncancelable and nonrefundable. Furthermore, if a customer reduces the contracted usage or service level, the customer has no right of refund. The Company’s subscription arrangements do not provide customers with the right to take possession of the software supporting the platform and, as a result, are accounted for as service arrangements. This revenue recognition policy is consistent for sales generated directly with customers and sales generated indirectly through channel partners. The Company determines revenue recognition through the following steps: • Identification of the contract, or contracts, with a customer; • Identification of the performance obligations in the contract; • Determination of the transaction price; • Allocation of the transaction price to the performance obligations in the contract; and • Recognition of revenue when, or as, the Company satisfies a performance obligation. Subscription Revenue Subscription revenue, which includes support, is recognized on a straight-line basis over the noncancelable contractual term of the arrangement, generally beginning on the date that the Company’s service is made available to the customer. Professional Services Revenue The Company’s professional services principally consist of customer-specific requests for application integrations, user interface enhancements and other customer-specific requests. Revenue for the Company’s professional services is recognized as services are performed in proportion to their pattern of transfer. Contracts with Multiple Performance Obligations Some of the Company’s contracts with customers contain multiple performance obligations. For these contracts, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to the separate performance obligations on a relative SSP basis. The Company determines SSP based on observable, if available, prices for those related services when sold separately. When such observable prices are not available, the Company determines SSP based on overarching pricing objectives and strategies, taking into consideration market conditions and other factors, including customer size, volume purchased, market and industry conditions, product-specific factors and historical sales of the deliverables. Deferred Revenue Deferred revenue consists of customer billings in advance of revenue being recognized from the Company’s subscription and support services and professional services arrangements. The Company primarily invoices its customers for its subscription services arrangements annually in advance. The Company’s payment terms generally provide that customers pay the invoiced portion of the total arrangement fee within 30 days of the invoice date. Amounts anticipated to be recognized within one year of the balance sheet date are recorded as deferred revenue, current; the remaining portion is recorded as deferred revenue, noncurrent in the consolidated balance sheets. Deferred Commissions Sales commissions earned by the Company’s sales force are considered incremental and recoverable costs of obtaining a contract with a customer. Sales commissions for new revenue contracts, including incremental sales to existing customers, are deferred and then amortized on a straight-line basis over a period of benefit, which the Company has determined to be generally five years. The Company determined the period of benefit by taking into consideration its customer contracts, its technology and other factors. Sales commissions for renewal contracts (which are not considered commensurate with sales commissions for new revenue contracts and incremental sales to existing customers) are deferred and then amortized on a straight-line basis over the related period of benefit, which is generally the related contract renewal term. Amortization expense is included in sales and marketing expenses in the accompanying consolidated statements of operations. Sales commissions capitalized as contract costs totaled $41.3 million and $27.0 million in the years ended January 31, 2019 and 2018 , respectively. Amortization of contract costs was $20.9 million , $15.2 million and $10.5 million for the years ended January 31, 2019 , 2018 and 2017 , respectively. There was no impairment loss in relation to the costs capitalized. Cost of Revenue Costs of revenue primarily consist of costs related to providing the Company’s cloud-based platform to its customers, including third-party hosting fees, amortization of capitalized internal-use software and finite-lived purchased developed technology, customer support, other employee-related expenses for security, technical operations and professional services staff, and allocated overhead costs. Cash, Cash Equivalents and Restricted Cash Cash and cash equivalents consist of cash on hand and highly liquid investments with original maturities of three months or less from the date of purchase. Cash equivalents generally consist of investments in money market funds. The fair market value of cash equivalents approximated their carrying value as of January 31, 2019 and 2018 . As of January 31, 2019 and 2018 , the Company's long-term restricted cash balance was $11.4 million and $8.3 million , respectively, related to letters of credit for its facility lease agreements. Long-term restricted cash is included within other assets on the Company's consolidated balance sheet. Short-term Investments The Company’s short-term investments comprise asset-backed securities, U.S. treasury securities and corporate debt securities. The Company determines the appropriate classification of its short-term investments at the time of purchase and reevaluates such designation at each balance sheet date. The Company has classified and accounted for its short-term investments as available-for-sale securities as the Company may sell these securities at any time for use in its current operations or for other purposes, even prior to maturity. As a result, the Company classifies its short-term investments, including securities with stated maturities beyond twelve months, within current assets in the consolidated balance sheets. Available-for-sale securities are recorded at fair value each reporting period. Unrealized gains and losses on these short-term investments are reported as a separate component of accumulated other comprehensive loss in the consolidated balance sheets until realized. Interest income is reported within other income (expense), net in the consolidated statements of operations. The Company periodically evaluates its short-term investments to assess whether those with unrealized loss positions are other-than-temporarily impaired. The Company considers various factors in determining whether to recognize an impairment charge, including the length of time the investment has been in a loss position, the extent to which the fair value is less than the Company’s cost basis, the investment’s financial condition and near-term prospects of the investee. Realized gains and losses are determined based on the specific identification method and are reported in other income (expense), net in the consolidated statements of operations. If the Company determines that the decline in an investment’s fair value is other-than-temporary, the difference is recognized as an impairment loss in the consolidated statements of operations. Accounts Receivable and Allowances Accounts receivable are recorded at the invoiced amount, net of allowances. These allowances are based on the Company’s assessment of the collectibility of accounts by considering the age of each outstanding invoice, the collection history of each customer and an evaluation of potential risk of loss associated with delinquent accounts. Amounts deemed uncollectible are recorded to these allowances in the consolidated balance sheets with an offsetting decrease in related deferred revenue and a charge to general and administrative expense in the consolidated statement of operations. Property and Equipment Property and equipment, net, is stated at cost less accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the respective assets. Repairs and maintenance costs are expensed as incurred. The useful lives of property and equipment are as follows: Useful lives Capitalized internal-use software costs 3 years Computers and equipment 3 years Furniture and fixtures 7 years Leasehold improvements Shorter of estimated useful life or remaining lease term Capitalized Internal-Use Software Costs The Company capitalizes as intangible assets certain costs incurred during the application development stage in connection with software development for its platform. Costs related to preliminary project activities and post-implementation activities are expensed as incurred. Capitalized costs are recorded as part of intangible assets. Maintenance and training costs are expensed as incurred. Capitalized internal-use software costs are amortized on a straight-line basis over the software’s estimated useful life, which is generally three years . The Company records amortization related to capitalized internal-use software within subscription cost of revenue in the consolidated statements of operations. The Company evaluates the useful lives of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets. Business Combinations When the Company acquires a business, the purchase price is allocated to the net tangible and identifiable intangible assets acquired. Any residual purchase price is recorded as goodwill. The allocation of the purchase price requires management to make estimates in determining the fair values of assets acquired and liabilities assumed, especially with respect to intangible assets. These estimates can include, but are not limited to, the cash flows that an asset is expected to generate in the future, the appropriate weighted-average cost of capital and the cost savings expected to be derived from acquiring an asset. These estimates are inherently uncertain and unpredictable. During the measurement period, which may be up to one year from the acquisition date, adjustments to the fair value of these tangible and intangible assets acquired and liabilities assumed may be recorded, with the corresponding offset to goodwill. Upon the conclusion of the measurement period or final determination of the fair value of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to the consolidated statements of operations. Goodwill and Other Long-Lived Assets The excess of the purchase price over the estimated fair value of net assets of businesses acquired in a business combination is recognized as goodwill. Goodwill is tested for impairment annually on November 1 st or more frequently if certain indicators are present. Long-lived assets, such as property and equipment and finite-lived intangible assets subject to amortization are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of any asset may not be recoverable. Recoverability of assets to be held and used is measured by comparing the carrying amount to the estimated undiscounted future cash flows expected to be generated. If the carrying amount exceeds the undiscounted cash flows, the assets are determined to be impaired and an impairment charge is recognized as the amount by which the carrying amount exceeds its fair value. The Company amortizes intangible assets with finite lives on a straight-line basis over their estimated useful lives in cost of revenue in the consolidated statements of operations. Convertible Senior Notes The 2023 Notes are accounted for in accordance with FASB ASC Subtopic 470‑20, Debt with Conversion and Other Options. Pursuant to ASC Subtopic 470‑20, issuers of certain convertible debt instruments, such as the 2023 Notes, that have a net settlement feature and may be settled wholly or partially in cash upon conversion are required to separately account for the liability (debt) and equity (conversion option) components of the instrument. The carrying amount of the liability component of the instrument is computed by estimating the fair value of a similar liability without the conversion option. The amount of the equity component is then calculated by deducting the fair value of the liability component from the principal amount of the instrument. The difference between the principal amount and the liability component represents a debt discount that is amortized to interest expense over the respective term of the 2023 Notes using the effective interest rate method. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. In accounting for the issuance costs related to the 2023 Notes, the allocation of issuance costs incurred between the liability and equity components was based on their relative values. Advertising Expenses Advertising costs are expensed as incurred. Advertising expense was $10.0 million , $9.4 million , and $4.4 million for the years ended January 31, 2019 , 2018 and 2017 . Stock-Based Compensation Stock-based compensation issued to employees and non-employees, including the purchase rights issued under the Company's 2017 Employee Stock Purchase Plan (ESPP), is measured based on the grant-date fair value of the awards and recognized as an expense following the straight-line attribution method over the requisite service period for stock options, restricted stock units (RSUs) and restricted stock, and over the offering period for the purchase rights issued under the ESPP. The Company’s use of the Black-Scholes option-pricing model to estimate the fair value of stock options granted requires the input of highly subjective assumptions. These assumptions and estimates are as follows: Fair value — Prior to the IPO, the Company's stock was not publicly traded and it estimated the fair value of common stock using various methodologies, including valuation analyses performed by third-party valuation firms. After the IPO, the Company used the publicly quoted price as reported on the Nasdaq Global Select Market as the fair value of its common stock. Expected volatility — Expected volatility is a measure of the amount by which the stock price is expected to fluctuate. Since the Company does not have sufficient trading history of its common stock, it estimates the expected volatility of its stock options at their grant date by taking the weighted-average historical volatility of a group of comparable publicly-traded companies over a period equal to the expected life of the options. Expected term — The Company determines the expected term based on the average period the stock options are expected to remain outstanding, generally calculated as the midpoint of the stock option’s vesting term and contractual expiration period, as the Company does not have sufficient historical information to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior. Risk-free rate — The Company uses the U.S. Treasury yield that corresponds with the expected term. Expected dividend yield — The Company utilizes a dividend yield of zero , as it does not currently issue dividends and does not expect to in the future. Income Taxes The Company accounts for income taxes in accordance with the liability method of accounting for income taxes. Under this method, the Company recognizes deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial reporting and tax basis of assets and liabilities, as well as for operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates that are expected to apply to taxable income for the years in which those tax assets and liabilities are expected to be realized or settled. The Company records a valuation allowance to reduce its deferred tax assets to the net amount that the Company believes is more likely than not to be realized. In assessing the need for a valuation allowance, the Company has considered its historical levels of income, expectations of future taxable income and ongoing tax planning strategies. Because of the uncertainty of the realization of the deferred tax assets, the Company has recorded a full valuation allowance against its deferred tax assets. Realization of its deferred tax assets is dependent primarily upon future U.S. taxable income. The Company recognizes and measures tax benefits from uncertain tax positions using a two-step approach. The first step is to evaluate the tax position taken or expected to be taken by determining if the weight of available evidence indicates that it is more likely than not that the tax position will be sustained in an audit, including resolution of any related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement. Significant judgment is required to evaluate uncertain tax positions. Although the Company believes that it has adequately reserved for its uncertain tax positions, it can provide no assurance that the final tax outcome of these matters will not be materially different. The Company evaluates its uncertain tax position on a regular basis and evaluations are based on a number of factors, including changes in facts and circumstances, changes in tax law, correspondence with tax authorities during the course of an audit and effective settlement of audit issues. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will affect the provision for income taxes in the period in which such determination is made and could have a material impact on the Company’s financial condition and results of operations. The provision for income taxes includes the effects of any accruals that the Company believes are appropriate, as well as the related net interest and penalties. Facility Leases Certain facility lease agreements contain rent holidays, allowances and rent escalation provisions. For these leases, the Company recognizes the related rental expense on a straight-line basis over the lease period of the facility and records the difference between amounts charged to operations and amounts paid as deferred rent. These rent holidays, allowances and rent escalations are considered in determining the straight-line expense to be recorded over the lease term. Concentrations of Risk and Significant Customers The Company’s financial instruments that are exposed to concentrations of credit risk consist primarily of cash and cash equivalents, short-term investments and accounts receivable. Cash and cash equivalents and short-term investments are currently held in two financial institutions and, at times, may exceed federally insured limits. As of January 31, 2019 and 2018 and for each of the three years ended January 31, 2019 , no single customer represented greater than 10% of accounts receivable or greater than 10% of revenue, respectively. In order to reduce the risk of downtime of the Company’s subscription services, the Company utilizes data center facilities operated by third parties located in Virginia, Oregon, Germany and Ireland. The Company has internal procedures to restore services in the event of disaster at any of its current data center facilities. Even with these procedures for disaster recovery in place, the Company’s subscription services could be significantly interrupted during the time period following a disaster at one of its sites and the subsequent restoration of services at another site. Geographical Information Revenue by location is determined by the billing address of the customer. The following table sets forth revenue by geographic area (in thousands): Year Ended January 31, 2019 2018 2017 United States $ 337,367 $ 217,300 $ 135,364 International 61,887 39,247 25,442 Total $ 399,254 $ 256,547 $ 160,806 Other than the United States, no individual country exceeded 10% of total revenue for the years ended January 31, 2019 , 2018 and 2017 . Property and equipment by geographic location is based on the location of the legal entity that owns the asset. As of January 31, 2019 and 2018 , substantially all of the Company’s property and equipment was located in the United States. Net Loss per Share The Company computes basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method required for participating securities. Under the two-class method, basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase, without consideration for potentially dilutive securities as they do not share in losses. The diluted net loss per share attributable to common stockholders is computed giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, options to purchase common stock, unvested RSUs, purchase rights issued under the ESPP, shares subject to repurchase from early exercised options, unvested common stock and restricted stock issued in connection with certain business combinations, convertible senior notes and warrants are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as the effect is antidilutive. Since the Company's IPO, Class A and Class B common stock are the only outstanding equity of the Company. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion rights. See Note 14. Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). Topic 606 supersedes the revenue recognition requirements in Accounting Standards Codification (ASC) Topic 605, Revenue Recognition (Topic 605), and requires the recognition of revenue when promised goods or services are transferred to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. Topic 606 also includes Subtopic 340-40, Other Assets and Deferred Costs - Contracts with Customers, which requires the deferral of incremental costs of obtaining a contract with a customer. Collectively, the Company refers to Topic 606 and Subtopic 340-40 as "ASC 606." The Company adopted the requirements of ASC 606 as of February 1, 2018, utilizing the full retrospective method of transition. Adoption of ASC 606 resulted in changes to the Company’s accounting policies for revenue recognition and deferred commissions as detailed below. The Company applied ASC 606 using a practical expedient where the consideration allocated to the remaining performance obligations and an explanation of when the Company expects to recognize that amount as revenue for all reporting periods presented before the date of the initial application is not disclosed. The impact of adopting ASC 606 on fiscal 2018 and 2017 revenue is not material. The primary impact of adopting ASC 606 relates to the deferral of incremental costs of obtaining contracts, primarily consisting of sales commissions. Under Topic 605, the Company deferred only direct and incremental commission costs to obtain a contract and amortized those costs on a straight-line basis over the term of the related contract, which was generally one to three years . Under ASC 606, the Company defers all incremental commission costs to obtain the contract. The Company amortizes these costs on a straight-line basis over a period of benefit, determined to be generally five years or the related contractual renewal term. The Company adjusted its consolidated financial statements from amounts previously reported due to the adoption of ASC 606. Select consolidated statement of operations line items, which reflect the adoption of ASC 606, are as follows (in thousands except per share data): Year Ended January 31, 2018 2017 As Reported Adoption of ASU 2014-09 As Adjusted As Reported Adoption of ASU 2014-09 As Adjusted Revenue Subscription $ 239,177 $ (2,755 ) $ 236,422 $ 143,136 $ 1,773 $ 144,909 Professional services and other 20,813 (688 ) 20,125 17,190 (1,293 ) 15,897 Total revenue 259,990 (3,443 ) 256,547 160,326 480 160,806 Sales and marketing 172,973 (7,953 ) 165,020 118,742 (7,973 ) 110,769 Total operating expenses 295,597 (7,953 ) 287,644 187,500 (7,973 ) 179,527 Net loss (114,359 ) 4,510 (109,849 ) (83,509 ) 8,453 (75,056 ) Net loss per share, basic and diluted $ (1.38 ) $ 0.06 $ (1.32 ) $ (4.39 ) $ 0.45 $ (3.94 ) Select consolidated balance sheet line items, which reflect the adoption of ASC 606, are as follows (in thousands): As of January 31, 2018 As Reported Adoption of ASU 2014-09 As Adjusted Assets Current assets: Deferred commissions $ 16,481 $ 1,274 $ 17,755 Prepaid expenses and other current assets 16,973 808 17,781 Total current assets 315,416 2,082 317,498 Deferred commissions, noncurrent 10,971 29,784 40,755 Total assets $ 367,397 $ 31,866 $ 399,263 Liabilities and stockholders’ equity Deferred revenue $ 162,633 $ (2,817 ) $ 159,816 Total current liabilities 190,760 (2,817 ) 187,943 Deferred revenue, noncurrent 6,034 (1,071 ) 4,963 Total liabilities 203,811 (3,888 ) 199,923 Accumulated deficit (402,468 ) 35,754 (366,714 ) Total stockholders’ equity $ 163,586 $ 35,754 $ 199,340 The adoption of ASC 606 had no impact on cash provided by or used in operating, investing, or financing activities in the Company’s consolidated statement of cash flows. Additionally, the adoption of ASC 606 did not have a material impact on the provision for (benefit from) income taxes. The adoption adjustments impacted the deferred income taxes pertaining to the U.S. entity which are subject to a full valuation allowance. In February 2018, the FASB issued ASU No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (ASU 2018-02). Under existing U.S. GAAP, the effects of changes in tax rates and laws on deferred tax balances are recorded as a component of income tax expense in the period in which the law was enacted. When deferred tax balances related to items originally recorded in accumulated other comprehensive income (loss) are adjusted, certain tax effects become stranded in accumulated other comprehensive income. The amendments in ASU 2018-02 allow a reclassification from accumulated other comprehensive income (loss) to retained earnings (accumulated deficit) for stranded income tax effects resulting from the 2017 Tax Cuts and Jobs Act. The amendments in this ASU also require certain disclosures about stranded income tax effects. The guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption in any period is permitted. The Company’s provisional adjustments recorded in fiscal 2018 to account for the impact of the 2017 Tax Cuts and Jobs Act did not result in stranded tax effects. The early adoption of this standard did not have a material impact on the Company’s consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07, Compensation - Stock Compensation (Topic 718) Improvements to Non-Employee Share Based Payment Accounting (ASU 2018-07), with an intent to reduce cost and complexity and to improve financial reporting for share-based payments issued to non-employees. The amendments in ASU 2018-07 provide for the simplification of the measurement of share-based payment transactions for acquiring goods and services from non-employees. This standard expands the scope of Topic 718 to include share-based payments issued to non-employees for goods or services, aligning the accounting for share-based payments to non-employees and employees. This guidance is effective for annual and interim periods beginning after December 15, 2018, and early adoption is permitted. The early adoption of this standard did not have a material impact on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (ASU 2018-13), which amends ASC 820, Fair Value Measurement. ASU 2018-13 modifies the disclosure requirements for fair value measurements by removing, modifying or adding certain disclosures. This guidance is effective for the Company on February 1, 2020, with early adoption permitted for the removal and modification of disclosures and delayed adoption until February 1, 2020 permitted for the new disclosures. The removed and modified disclosures have been adopted on a retrospective basis, and the new disclosures have been adopted on a prospective basis. The early adoption of this standard did not have a material impact on the Company’s consolidated financial statements. Recent Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02 (Topic 842), Leases (ASU 2016-02), which supersedes the guidance in topic ASC 840, Leases. The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease. A lessee is also required to record a right-of-use asset (ROU) and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The Company will be required to recognize and measure leases existing at, or entered into after, the beginning of the earliest comparative period presented using a modified retrospective approach, with certain practical expedients available. ASU 2016-02 is effective for the Company beginning February 1, 2019. The Company expects to elect the available practical expedients on adoption. The Company is assessing the impact of ASU 2016-02 on its internal controls over financial reporting. Adoption of ASU 2016-02 will have a material impact on the Company's consolidated balance sheets, but will not have a material impact on the Company's consolidated income statements and taxes. The most significant impact will be the recognition of ROU assets and lease liabilities for operating leases. The Company expects adoption of the standard will result in the recognition of additional ROU assets and lease liabilities for operating leases in the range of approximately $121 million to $126 million , and $158 million to $163 million , respectively, as of January 31, 2019 . Additionally, the adoption of this standard will have no impact to cash provided by or used in operating, financing, or investing activities on the Company's consolidated cash flows statements. In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (ASU 2018-15), which requires a customer in a cloud computing arrangement that is a service contract to follow the internal-use software guidance in Account

Business Combinations

Business Combinations	12 Months Ended
	Jan. 31, 2019
Business Combinations [Abstract]
Business Combinations	Business Combinations Stormpath On February 17, 2017, the Company acquired the rights to hire certain employees and a non-exclusive intellectual property license from Stormpath, Inc. (Stormpath), a privately-held technology company which had built a user management and authentication service for software development teams. The transaction has been accounted for as a business combination. The total consideration of $3.7 million , consisting of 200,000 shares of common stock valued at $2.2 million , at the time of the transaction, issued to Stormpath and replacement awards valued at $1.5 million issued to the hired employees, was recognized as goodwill. In addition, the Company issued an incremental 800,000 shares of restricted common stock valued at $8.6 million , at the time of the transaction, which is being recognized as post-combination stock-based compensation expense. See Note 12 for further details. ScaleFT On July 13, 2018, the Company acquired all issued and outstanding capital stock of ScaleFT, Inc. (ScaleFT), a “zero trust” security company which provides access solutions for the modern workforce. The acquisition date cash consideration transferred for ScaleFT was $15.6 million , net of $0.6 million in cash received. The Company recorded $4.6 million for developed technology intangible assets with estimated useful life of three years and $11.8 million of goodwill which is primarily attributed to the assembled workforce as well as the integration of ScaleFT’s technology and the Company’s technology. The Company incurred $1.1 million of acquisition related costs, which were recorded in the quarter ended July 31, 2018.

Cash Equivalents and Short-term

Cash Equivalents and Short-term Investments	12 Months Ended
	Jan. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Cash Equivalents and Short-term Investments	Cash Equivalents and Short-term Investments The amortized costs, unrealized gains and losses and estimated fair values of the Company’s cash equivalents and short-term investments as of January 31, 2019 and 2018 were as follows (in thousands): As of January 31, 2019 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Cash equivalents: Money market funds $ 247,426 $ — $ — $ 247,426 Corporate debt securities 3,409 — (1 ) 3,408 Total cash equivalents 250,835 — (1 ) 250,834 Short-term investments: U.S. treasury securities 195,913 37 (53 ) 195,897 Corporate debt securities 69,483 13 (19 ) 69,477 Total short-term investments 265,396 50 (72 ) 265,374 Total $ 516,231 $ 50 $ (73 ) $ 516,208 As of January 31, 2018 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Cash equivalents: Money market funds $ 90,770 $ — $ — $ 90,770 Total cash equivalents 90,770 — — 90,770 Short-term investments: Commercial paper 15,946 — — 15,946 U.S. treasury securities 61,896 — (158 ) 61,738 Corporate debt securities 24,125 — (44 ) 24,081 Total short-term investments 101,967 — (202 ) 101,765 Total $ 192,737 $ — $ (202 ) $ 192,535 All short-term investments were designated as available-for-sale securities as of January 31, 2019 and 2018 . The following tables present the contractual maturities of the Company’s short-term investments as of January 31, 2019 and 2018 (in thousands): As of January 31, 2019 As of January 31, 2018 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Due within one year $ 265,396 $ 265,374 $ 93,421 $ 93,237 Due between one to five years — — 8,546 8,528 Total $ 265,396 $ 265,374 $ 101,967 $ 101,765 The Company had 34 and 23 short-term investments in unrealized loss positions as of January 31, 2019 and 2018 , respectively. There were no material gross unrealized gains or losses from available-for-sale securities and no material realized gains or losses from available-for-sale securities that were reclassified out of accumulated other comprehensive income for the years ended January 31, 2019 , 2018 and 2017 . For available-for-sale debt securities that have unrealized losses, the Company evaluates whether (i) it has the intention to sell any of these investments and (ii) whether it is not more likely than not that it will be required to sell any of these available-for-sale debt securities before recovery of the entire amortized cost basis. Based on this evaluation, the Company determined that there were no other-than-temporary impairments associated with short-term investments as of January 31, 2019 and 2018 .

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Jan. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company measures its financial assets at fair value each reporting period using a fair value hierarchy that prioritizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure as follows: Level 1-Valuations based on observable inputs that reflect quoted prices for identical assets or liabilities in active markets. Level 2-Valuations based on other inputs that are directly or indirectly observable in the marketplace. Level 3-Valuations based on unobservable inputs that are supported by little or no market activity. Assets and Liabilities Measured at Fair Value on a Recurring Basis The following table presents information about the Company’s financial assets that are measured at fair value on a recurring basis using the above input categories (in thousands): As of January 31, 2019 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 247,426 $ — $ — $ 247,426 Corporate debt securities — 3,408 — 3,408 Total cash equivalents 247,426 3,408 — 250,834 Short-term investments: U.S. treasury securities — 195,897 — 195,897 Corporate debt securities — 69,477 — 69,477 Total short-term investments — 265,374 — 265,374 Total cash equivalents and short-term investments $ 247,426 $ 268,782 $ — $ 516,208 As of January 31, 2018 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 90,770 $ — $ — $ 90,770 Total cash equivalents 90,770 — — 90,770 Short-term investments: Commercial paper — 15,946 — $ 15,946 U.S. treasury securities — 61,738 — $ 61,738 Corporate debt securities — 24,081 — 24,081 Total short-term investments — 101,765 — 101,765 Total cash equivalents and short-term investments $ 90,770 $ 101,765 $ — $ 192,535 The carrying amounts of certain financial instruments, including cash held in banks, accounts receivable and accounts payable approximate fair value due to their short-term maturities and are excluded from the fair value table above. Fair Value Measurements of Other Financial Instruments The following table presents the carrying amounts and estimated fair values of our financial instruments that are not recorded at fair value on the consolidated balance sheets (in thousands): As of January 31, 2019 Net Carrying Amount Estimated Convertible senior notes $ 278,231 $ 620,565 The difference between the principal amount of the 2023 Notes, $345.0 million , and the net carrying amount before unamortized debt issuance costs represents the unamortized debt discount (See Note 9 for additional details). The estimated fair value of the 2023 Notes, which the Company has classified as Level 2 financial instruments, was determined based on the quoted bid price of the convertible senior notes in an over-the-counter market on the last trading day of the reporting period. As of January 31, 2019 , the difference between the net carrying amount of the 2023 Notes and estimated fair value represents the equity conversion value premium the market assigned to the 2023 Notes. Based on the closing price of our common stock of $82.43 on January 31, 2019 , the if-converted value of the 2023 Notes exceeded the principal amount of $345.0 million .

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, net	12 Months Ended
	Jan. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets, net	Goodwill and Intangible Assets, net Goodwill As of January 31, 2019 and 2018 , goodwill was $18.1 million and $6.3 million , respectively. No goodwill impairments were recorded during the years ended January 31, 2019 , 2018 and 2017 . Goodwill balances as of January 31, 2019 and 2018 were as follows (in thousands): Balance at January 31, 2018 $ 6,282 Goodwill recorded in connection with ScaleFT acquisition 11,807 Balance at January 31, 2019 $ 18,089 Intangible Assets, net Intangible assets consisted of the following (in thousands): As of January 31, 2019 Gross Accumulated Amortization Write-offs Net Capitalized internal-use software costs $ 19,838 $ (9,969 ) $ — $ 9,869 Purchased developed technology 4,600 (833 ) — 3,767 Software licenses 1,023 (763 ) — 260 $ 25,461 $ (11,565 ) $ — $ 13,896 As of January 31, 2018 Gross Accumulated Amortization Write-offs Net Capitalized internal-use software costs $ 17,511 $ (5,172 ) $ (1,077 ) $ 11,262 Software licenses 1,094 (558 ) (37 ) 499 $ 18,605 $ (5,730 ) $ (1,114 ) $ 11,761 The Company capitalized $3.4 million and $6.7 million of internal-use software during the years ended January 31, 2019 and 2018 , respectively, which included $0.5 million and $1.2 million of stock-based compensation costs, respectively. Amortization expense of capitalized internal-use software costs totaled $4.8 million , $2.7 million and $1.6 million during the years ended January 31, 2019 , 2018 and 2017 , respectively. The Company wrote-off $1.1 million of previously capitalized costs in the year ended January 31, 2018 as they were not realizable. The charge was recognized in research and development in the consolidated statements of operations. Amortization expense of intangible assets for the years ended January 31, 2019 , 2018 and 2017 was $5.8 million , $2.9 million , and $1.8 million , respectively. As of January 31, 2019 , estimated remaining amortization expense for the intangible assets by fiscal year is as follows (in thousands): 2020 6,302 2021 4,789 2022 1,459 2023 1,346 Total $ 13,896

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Jan. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Property and Equipment, net Property and equipment consisted of the following (in thousands): As of January 31, 2019 2018 Computers and equipment $ 3,668 $ 5,384 Furniture and fixtures 11,012 7,083 Leasehold improvements 47,883 8,188 Property and equipment, gross 62,563 20,655 Less accumulated depreciation (9,642 ) (8,115 ) Property and equipment, net $ 52,921 $ 12,540 Depreciation expense was $5.7 million , $4.0 million and $2.4 million for the years ended January 31, 2019 , 2018 and 2017 , respectively. Allowances The Company’s allowances for the years ended January 31, 2019 , 2018 and 2017 are as follows (in thousands): As of January 31, 2019 2018 2017 Balance, beginning of period $ 1,472 $ 1,306 $ 861 Additions 888 431 1,185 Write-offs (262 ) (265 ) (740 ) Balance, end of period $ 2,098 $ 1,472 $ 1,306 Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): As of January 31, 2019 2018 Deposit related to early exercise of unvested options $ 370 $ 1,119 Accrued expenses 6,392 3,389 Accrued taxes payable 1,195 835 Deferred rent, current 2,002 520 Other — 324 Accrued expenses and other current liabilities $ 9,959 $ 6,187 Other Liabilities, noncurrent Other liabilities, noncurrent consisted of the following (in thousands): As of January 31, 2019 2018 Deferred rent, noncurrent $ 35,980 $ 5,010 Deferred tax liabilities 727 175 Other 2,292 1,832 Other liabilities, noncurrent $ 38,999 $ 7,017

Deferred Revenue and Performanc

Deferred Revenue and Performance Obligations	12 Months Ended
	Jan. 31, 2019
Revenue from Contract with Customer [Abstract]
Deferred Revenue and Performance Obligations	Deferred Revenue and Performance Obligations Deferred Revenue Deferred revenue, which is a contract liability, consists primarily of payments received in advance of revenue recognition under the Company’s contracts with customers and is recognized as the revenue recognition criteria are met. Subscription revenue recognized during the years ended January 31, 2019 and 2018 that was included in the deferred revenue balances at the beginning of the respective periods was $157.9 million and $104.6 million , respectively. Professional services and other revenue recognized in the years ended January 31, 2019 and 2018 from deferred revenue balances at the beginning of the respective periods was not material. Transaction Price Allocated to the Remaining Performance Obligations Transaction price allocated to the remaining performance obligations represents contracted revenue that has not yet been recognized, which includes deferred revenue for subscription contracts that have been invoiced and will be recognized as revenue in future periods. As of January 31, 2019 , total remaining noncancelable performance obligations under the Company’s subscription contracts with customers was approximately $728.9 million , and the Company expects to recognize revenue on approximately 53% of these remaining performance obligations over the next 12 months, with the balance to be recognized thereafter. Revenue from remaining performance obligations for professional services and other contracts as of January 31, 2019 was not material. Unbilled Receivables The Company receives payments from customers based on billing schedules as established in its contracts. Unbilled receivables and contract assets represent amounts for which the Company has recognized revenue in excess of billings pursuant to its revenue recognition policy. As of January 31, 2019 and January 31, 2018 , contract assets and unbilled receivables were $1.5 million and $0.8 million , respectively, which are included in prepaid expenses and other current assets in the consolidated balance sheets.

Debt and Financing Arrangements

Debt and Financing Arrangements	12 Months Ended
	Jan. 31, 2019
Debt Disclosure [Abstract]
Debt and Financing Arrangements	Debt and Financing Arrangements Convertible Senior Notes The 2023 Notes are senior, unsecured obligations of the Company, and bear interest at a fixed rate of 0.25% per year. Interest is payable in cash semi-annually in arrears on February 15 and August 15 of each year, beginning on August 15, 2018. The 2023 Notes mature on February 15, 2023 unless earlier repurchased or converted. The Company may not redeem the 2023 Notes prior to maturity. The total net proceeds from the 2023 Notes, after deducting initial purchasers’ discounts and debt issuance costs, was approximately $335.0 million . The terms of the 2023 Notes are governed by an Indenture by and between the Company and Wilmington Trust, National Association, as Trustee (the Indenture). Upon conversion, the 2023 Notes may be settled in cash, shares of Class A common stock or a combination of cash and shares of Class A common stock, at the Company’s election. It is the Company’s current intent to settle the principal amount of the 2023 Notes with cash. The 2023 Notes are convertible at an initial conversion rate of 20.6795 shares of Class A common stock per $1,000 principal amount of 2023 Notes, which is equal to an initial conversion price of approximately $48.36 per share of Class A common stock, subject to adjustment under certain circumstances in accordance with the terms of the Indenture. Prior to the close of business on the business day immediately preceding October 15, 2022, holders of the 2023 Notes may convert all or a portion of their 2023 Notes only in multiples of $1,000 principal amount, under the following circumstances: • during any fiscal quarter commencing after the fiscal quarter ending on April 30, 2018 (and only during such fiscal quarter), if the last reported sale price of Class A common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding fiscal quarter is greater than or equal to 130% of the conversion price of the 2023 Notes on each applicable trading day; • during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of the 2023 Notes for each trading day of that five consecutive trading day period was less than 98% of the product of the last reported sale price of Class A common stock and the conversion rate on such trading day; or • upon the occurrence of specified corporate events, as described in the Indenture. On or after October 15, 2022 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their 2023 Notes regardless of the foregoing circumstances. For at least twenty trading days during the period of thirty consecutive trading days ended January 31, 2019 , the last reported sale price of the Company’s common stock was equal to or exceeded 130% of the conversion price of the 2023 Notes on each applicable trading day. As a result, the 2023 Notes are convertible at the option of the holders during the fiscal quarter ending April 30, 2019 and were classified as current liabilities on the consolidated balance sheet as of January 31, 2019 . As of the date of this filing, none of the holders of the 2023 Notes have submitted requests for conversion. Holders of the 2023 Notes who convert their 2023 Notes in connection with certain corporate events that constitute a make-whole fundamental change (as defined in the Indenture) are, under certain circumstances, entitled to an increase in the conversion rate. Additionally, in the event of a corporate event that constitutes a fundamental change (as defined in the Indenture), holders of the 2023 Notes may require the Company to repurchase all or a portion of their 2023 Notes at a price equal to 100% of the principal amount of the 2023 Notes being repurchased, plus any accrued and unpaid interest. In accounting for the issuance of the 2023 Notes, the Company separated the 2023 Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of similar liabilities that do not have associated convertible features. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the 2023 Notes. The Company bifurcated the conversion option of the 2023 Notes from the debt instrument, classified the conversion option in equity and will accrete the resulting debt discount as interest expense over the contractual term of the 2023 Notes using the effective interest rate method. The equity component is not remeasured as long as the Notes continue to meet the conditions for equity classification. The effective interest rate of the liability component of the 2023 Notes is 5.68% . This interest rate was based on the interest rates of similar liabilities held by other companies with similar credit risk ratings at the time of issuance that did not have associated convertible features. The following table sets forth total interest expense recognized related to the 2023 Notes (in thousands): Year Ended January 31, 2019 Contractual interest expense $ 793 Amortization of debt issuance costs 1,085 Amortization of debt discount 13,194 Total $ 15,072 Total issuance costs of $10.0 million related to the 2023 Notes were allocated between liability and equity in the same proportion as the allocation of the total proceeds to the liability and equity components. Issuance costs attributable to the liability component are being amortized to interest expense over the respective term of the 2023 Notes using the effective interest rate method. The issuance costs attributable to the equity component were netted against the respective equity component in Additional paid-in capital. The Company recorded liability issuance costs of $7.7 million and equity issuance costs of $2.3 million . The 2023 Notes, net consisted of the following (in thousands): As of January 31, 2019 Liability component: Principal $ 345,000 Less: unamortized debt issuance costs and debt discount (73,372 ) Net carrying amount $ 271,628 Equity component: 2023 Notes $ 79,962 Less: issuance costs (2,320 ) Carrying amount of the equity component (1) $ 77,642 (1) Included in the consolidated balance sheets within Additional paid-in capital. Note Hedges In connection with the pricing of the 2023 Notes, the Company entered into convertible note hedge transactions with respect to its Class A common stock (the Note Hedges). The Note Hedges are purchased call options that give the Company the option to purchase, subject to anti-dilution adjustments substantially identical to those in the 2023 Notes, approximately 7.1 million shares of its Class A common stock for $48.36 per share (subject to adjustment), corresponding to the approximate initial conversion price of the 2023 Notes, exercisable upon conversion of the 2023 Notes. The Note Hedges will expire in 2023, if not exercised earlier. The Note Hedges are intended to offset potential dilution to the Company’s Class A common stock and/or offset the potential cash payments that the Company could be required to make in excess of the principal amount upon any conversion of the 2023 Notes under certain circumstances. The Note Hedges are separate transactions and are not part of the terms of the 2023 Notes. The Company paid an aggregate amount of $80.0 million for the Note Hedges. The amount paid for the Note Hedges was recorded as a reduction to Additional paid-in capital in the consolidated balance sheets. See Note 13 for the tax impacts of the 2023 Notes and Note Hedges. Warrants In connection with the issuance of the 2023 Notes, the Company also entered into separate warrant transactions pursuant to which it sold net-share-settled (or, at the Company’s election subject to certain conditions, cash-settled) warrants (the Warrants) to acquire, subject to anti-dilution adjustments, up to approximately 7.1 million shares over 80 scheduled trading days beginning in May 2023 of the Company’s Class A common stock at an initial exercise price of $68.06 per share (subject to adjustment). If the Warrants are not exercised on their exercise dates, they will expire. If the market value per share of the Company’s Class A common stock exceeds the applicable exercise price of the Warrants, the Warrants could have a dilutive effect on the Company’s Class A common stock unless, subject to the terms of the Warrants, the Company elects to cash settle the Warrants. The Warrants are separate transactions and are not part of the terms of the 2023 Notes or the Note Hedges. The Company received aggregate proceeds of $52.4 million from the sale of the Warrants in connection with the 2023 Notes. The proceeds from the sale of the Warrants was recorded as an increase to Additional paid-in capital in the consolidated balance sheets. Loan and Security Agreement The Company had a line of credit (Revolving Line) with Silicon Valley Bank (SVB) in the amount of $40.0 million , which expired by its terms in November 2018. The available amount, not to exceed $40.0 million , was based on certain revenue metrics and was reduced by letters of credit totaling $4.2 million established in connection with facility lease agreements. In November 2018, these letters of credit were secured by restricted cash and included in other assets on the consolidated balance sheet as of January 31, 2019 .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Jan. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases The Company leases office space under noncancelable operating leases for its San Francisco, California headquarters, as well as its offices in various cities in the United States, United Kingdom, Australia and Canada. These office leases expire on various dates through October 2028. In December 2017, the Company entered into a new corporate headquarters lease in San Francisco. This lease has a 10 year term, which expires in October 2028. The Company is entitled to two five -year options to extend this lease, subject to certain requirements. The total commitment is $206.3 million with a tenant improvement allowance of up to $24.7 million . The Company secured the lease obligation with an $8.0 million letter of credit, which is designated as restricted cash and included in other assets on its consolidated balance sheet as of January 31, 2019 . In conjunction with the execution of the leases, letters of credit in the aggregate amount of $12.7 million and $12.2 million were issued and outstanding as of January 31, 2019 and 2018 , respectively. No draws have been made under such letters of credit. In June 2018, the Company signed an agreement to sublease the premises at 634 2nd Street, San Francisco, California (2nd Street Sublease), which, together with the premises at 301 Brannan Street, San Francisco, California, comprise the Company’s former headquarters. The term of the 2nd Street Sublease agreement commenced on January 31, 2019. The 2nd Street Sublease and the master lease both expire in September 2024. The Company’s future income under the terms of the 2nd Street Sublease agreement will be approximately equal to the amount required to be paid by the Company to its landlord under the terms of the master lease. The Company and the sub-lessee executed a standby letter of credit amounting to $3.0 million to be held by the Company to secure the 2nd Street Sublease in the event of uncured default by the sub-lessee. Pursuant to a termination agreement pertaining to the Company’s lease of the premises at 301 Brannan Street, San Francisco, California, the non-cancellable lease term for those premises expired in January 2019. As of January 31, 2019 , the future minimum lease payments by fiscal year under various operating leases and purchase obligations, such as data center operations and sales and marketing activities, are as follows (in thousands): Operating Purchase Obligations Total 2020 $ 16,672 $ 19,668 $ 36,340 2021 26,606 15,101 41,707 2022 28,138 15,101 43,239 2023 27,777 10,000 37,777 2024 28,384 — 28,384 Thereafter 117,101 — 117,101 Total contractual obligations $ 244,678 $ 59,870 $ 304,548 Deferred rent was $38.0 million and $5.5 million as of January 31, 2019 and 2018 , respectively, and is included in accrued expenses and other current liabilities and other liabilities, noncurrent in the consolidated balance sheets. Rent expense was $23.3 million , $10.6 million and $7.4 million for the years ended January 31, 2019 , 2018 and 2017 , respectively. Legal Matters From time to time in the normal course of business, the Company may be subject to various legal matters such as threatened or pending claims or proceedings. There were no material such matters as of January 31, 2019 and 2018 . Warranties and Indemnification The Company’s subscription services are generally warranted to perform materially in accordance with the Company’s online help documentation under normal use and circumstances. Additionally, the Company’s arrangements generally include provisions for indemnifying customers against liabilities if its subscription services infringe a third party’s intellectual property rights. Furthermore, the Company may also incur liabilities if it breaches the security or confidentiality obligations in its arrangements. To date, the Company has not incurred significant costs and has not accrued a liability in the accompanying consolidated financial statements as a result of these obligations. The Company has entered into service-level agreements with a majority of its customers defining levels of uptime reliability and performance and permitting those customers to receive credits for prepaid amounts related to unused subscription services if the Company fails to meet the defined levels of uptime. In very limited instances, the Company allows customers to early terminate their agreements in the event that the Company fails to meet those levels as they may constitute a breach of contract. If the customer did terminate, they would receive a refund of prepaid unused subscription fees. To date, the Company has not experienced any significant failures to meet defined levels of uptime reliability and performance as a result of those agreements and, as a result, the Company has not accrued any liabilities related to these agreements in the consolidated financial statements.

Common Stock and Stockholders'

Common Stock and Stockholders' Equity	12 Months Ended
	Jan. 31, 2019
Equity [Abstract]
Common Stock and Stockholders' Equity	Common Stock and Stockholders' Equity Redeemable Convertible Preferred Stock Immediately prior to the completion of the IPO in April 2017, all shares of redeemable convertible preferred stock then outstanding were converted into 59,491,640 shares of common stock on a one -to-one basis and then immediately reclassified into Class B common stock and additional paid-in capital. As of January 31, 2019 , there were no shares of redeemable convertible preferred stock issued and outstanding. Common Stock Immediately prior to the completion of the IPO, all shares of common stock then outstanding were reclassified into Class B common stock. Shares offered and sold in the IPO consisted of the newly authorized shares of Class A common stock. As of January 31, 2019 , and 2018 the Company had authorized 1,000,000,000 shares of Class A common stock and had authorized 120,000,000 shares of Class B common stock, each with par value $0.0001 per share. As of January 31, 2019 , 101,093,322 shares of Class A common stock and 11,059,181 shares of Class B common stock were issued and outstanding. Holders of Class A and Class B common stock are entitled to one vote per share and 10 votes per share, respectively, and the shares of Class A common stock and Class B common stock are identical, except for voting and conversion rights. Shares of Class B common stock may be converted into Class A common stock at any time at the option of the stockholder on a one -for-one basis, and are automatically converted into Class A common stock upon sale or transfer, subject to certain limited exceptions. Shares of Class A common stock are not convertible. As of January 31, 2019 , shares of common stock reserved for future issuance are as follows: Options and unvested RSUs outstanding 22,639,330 Available for future stock option and RSU grants 12,635,830 Available for ESPP 2,855,127 38,130,287 Awards Issued as Charitable Contributions During the year ended January 31, 2019 and 2018 , the Company issued 20,000 and 24,287 shares, respectively, of Class A common stock as charitable contributions and recognized $1.0 million and $0.7 million , respectively, as general and administrative expense in the consolidated statement of operations. During the year ended January 31, 2017 , the Company issued 13,935 shares of Class B common stock as charitable contributions and recognized $0.1 million as general and administrative expense in the consolidated statement of operations.

Employee Incentive Plans

Employee Incentive Plans	12 Months Ended
	Jan. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Employee Incentive Plans	Employee Incentive Plans The Company’s equity incentive plans provide for granting stock options, RSUs and restricted stock awards to employees, consultants, officers and directors. In addition, the Company offers an ESPP to eligible employees. Stock-based compensation expense by award type was as follows (in thousands): Year Ended January 31, 2019 2018 2017 Stock options $ 23,466 $ 24,186 $ 17,127 RSUs 41,637 9,104 — ESPP 7,248 7,111 — Restricted stock awards 1,608 3,281 — Restricted common stock 2,361 6,178 — Total $ 76,320 $ 49,860 $ 17,127 Stock-based compensation expense was recorded in the following cost and expense categories in the Company’s consolidated statements of operations (in thousands): Year Ended January 31, 2019 2018 2017 Cost of revenue: Subscription $ 7,837 $ 4,600 $ 1,979 Professional services and other 4,983 3,137 1,283 Research and development 22,642 18,107 2,992 Sales and marketing 22,916 13,242 6,029 General and administrative 17,942 10,774 4,844 Total $ 76,320 $ 49,860 $ 17,127 Stock-based compensation expense recorded to research and development in the consolidated statements of operations exclude amounts that were capitalized related to internal-use software for the years ended January 31, 2019 , 2018 and 2017 . Refer to Note 6 for additional details. Equity Incentive Plans The Company has two equity incentive plans: the 2009 Stock Plan (2009 Plan) and the 2017 Equity Incentive Plan (2017 Plan). Upon the completion of the Company’s IPO in April 2017, the Company ceased granting equity under the 2009 Plan, and all shares that remained available for future issuance under the 2009 Plan at that time were transferred to the 2017 Plan. As of January 31, 2019 , options to purchase 16,943,457 shares of Class B common stock and 860,337 shares of Class A common stock remain outstanding. As of January 31, 2019 , the total number of shares reserved for future Class A stock grants under the 2017 Plan was 12,635,830 shares, including shares transferred from the 2009 Plan. Stock Options Options issued to new employees under the Plan generally are exercisable for periods not to exceed ten years and generally vest over four years with 25% vesting after one year and with the remainder vesting monthly thereafter in equal installments. Shares offered under the Plan may be: (i) authorized but unissued shares or (ii) treasury shares. A summary of the Company’s stock option activity and related information is as follows: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding as of January 31, 2018 24,917,045 $ 7.37 7.6 $ 550,173 Granted 684,500 39.21 Exercised (6,576,700 ) 5.61 Canceled (1,221,051 ) 8.55 Outstanding as of January 31, 2019 17,803,794 $ 9.16 7.1 $ 1,304,446 As of January 31, 2019: Vested and expected to vest 17,803,794 $ 9.16 7.1 $ 1,304,446 Vested and exercisable 9,681,494 $ 6.82 6.6 $ 731,998 The weighted-average grant-date fair value of options granted was $ 17.21 , $5.40 and $4.00 during the years ended January 31, 2019 , 2018 and 2017 , respectively. The total grant-date fair value of stock options vested was $23.8 million , $23.9 million and $13.1 million during the years ended January 31, 2019 , 2018 and 2017 , respectively. The intrinsic value of the options exercised, which represents the difference between the fair market value of the Company’s common stock on the date of exercise and the exercise price of each option, was $309.3 million , $204.8 million and $6.9 million for the years ended January 31, 2019 , 2018 and 2017 , respectively. As of January 31, 2019 , there was a total of $37.3 million of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted-average period of 1.9 years . The Company used the Black-Scholes option pricing model to estimate the fair value of stock options granted with the following assumptions: Year Ended January 31, 2019 2018 2017 Expected volatility 40 % 40% - 41% 40% - 44% Expected term (in years) 6.3 6.3 - 6.4 5.5 - 6.9 Risk-free interest rate 2.70 % 1.87% - 2.21% 1.13% - 2.28% Expected dividend yield — — — Restricted Stock Units A summary of the Company’s RSU activities and related information is as follows: Number of Weighted- Outstanding as of January 31, 2018 2,862,929 $ 24.38 Granted 3,392,285 54.34 Vested (976,248 ) 23.92 Forfeited (443,430 ) 35.22 Outstanding as of January 31, 2019 4,835,536 $ 44.49 The Company granted 3,392,285 RSUs with an aggregate fair value of $184.3 million for the year ended January 31, 2019 . As of January 31, 2019 , there was $187.2 million of unrecognized stock-based compensation expense related to unvested RSUs, which is expected to be recognized over a weighted-average period of 3.1 years based on vesting under the award service conditions. Equity Awards Issued in Connection with Business Combinations In connection with the Stormpath transaction in February 2017, the Company issued 800,000 shares of restricted common stock to Stormpath with an aggregate fair value of $8.6 million to be recognized as post combination stock-based compensation. The restricted common stock vests ratably on the first and second anniversaries of the transaction date upon achievement of the respective performance conditions, and 400,000 of these shares vested during the year ended January 31, 2019 . The stock-based compensation expense related to the restricted common stock has a requisite service period of two years and will be recognized using an accelerated attribution method due to the existence of performance conditions. As of January 31, 2019 , there was $0.1 million of unrecognized compensation expense related to this restricted common stock which is expected to be recognized over the remaining weighted average life of 0.1 years . These shares of restricted common stock were separately authorized by the Company’s board of directors, and did not reduce the number of shares available for future issuance under the 2009 Plan or the 2017 Plan. The Company separately entered into retention arrangements with certain employees of Stormpath and issued 598,500 restricted stock awards under the 2009 Plan with an aggregate fair value of $6.6 million with performance conditions, including continued employment of certain employees with the Company and the wind down of the Stormpath, Inc. entity. The restricted stock awards vest ratably over two or three years from the transaction date, and 210,850 of these shares vested during the year ended January 31, 2019. Additionally, the Company granted 518,900 service-based stock options under the 2009 Plan to certain Stormpath employees with an aggregate fair value of $2.5 million to vest ratably over the requisite four -year service period. The restricted stock awards and stock options offered directly to Stormpath employees for employment with the Company are deemed replacement awards and a portion of such awards are considered compensation for pre-combination service. Of the $9.1 million total aggregate fair value of the awards, $1.5 million is related to pre-combination service and is recognized as goodwill and a reduction to the post-combination compensation expense. The post-combination expenses for the restricted stock awards and stock options are $5.5 million and $2.1 million , respectively. The expense related to the restricted stock awards is being recognized over two or three years based on an accelerated attribution method. The expense for the stock options is being recognized ratably over the requisite service period. As of January 31, 2019 , there was $0.6 million of unrecognized compensation expense related to unvested restricted stock awards, which is expected to be recognized over the remaining weighted average life of 0.5 years . As of January 31, 2019 , there was $1.1 million of unrecognized compensation cost related to unvested stock options, which is expected to be recognized over the remaining weighted average life of 1.4 years . The related stock options expense and activity are included within the Stock Options section above. Employee Stock Purchase Plan In February 2017, the Company’s board of directors adopted, and in March 2017, the Company’s stockholders approved the 2017 Employee Stock Purchase Plan, or the ESPP, which became effective prior to the completion of the IPO. The ESPP initially reserves and authorizes the issuance of up to a total of 3,000,000 shares of Class A common stock to participating employees. Except for the initial offering period, the ESPP provides for 12 -month offering periods beginning June 21 and December 21 of each year, and each offering period will consist of two six -month purchase periods. The initial offering period began April 7, 2017 and ended on June 20, 2018. The Company estimated the fair value of ESPP purchase rights using a Black-Scholes option pricing model with the following assumptions: Year Ended January 31, 2019 2018 Expected volatility 39% - 70% 32% - 38% Expected term (in years) 0.5 - 1.0 0.5 - 1.2 Risk-free interest rate 2.12% - 2.62% 0.95% - 1.73% Expected dividend yield — — During the year ended January 31, 2019 , the Company sold 615,210 shares of its common stock under the ESPP. The shares were purchased at a weighted-average purchase price of $22.31 with proceeds of $13.7 million . During the year ended January 31, 2018 , the Company sold 569,373 shares of its common stock under the ESPP. The shares were purchased at a weighted-average purchase price of $14.70 with proceeds of $8.4 million . As of January 31, 2019 , there was $4.2 million of unrecognized stock-based compensation expense related to the ESPP that is expected to be recognized over an average vesting period of 0.5 years .

Income Taxes

Income Taxes	12 Months Ended
	Jan. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The domestic and foreign components of pre-tax loss for the years ended January 31, 2019 , 2018 and 2017 are as follows (in thousands): Year Ended January 31, 2019 2018 2017 As Adjusted (1) As Adjusted (1) Domestic $ (128,214 ) $ (112,858 ) $ (76,485 ) Foreign 2,700 2,688 1,854 Loss before provision for (benefit from) income taxes $ (125,514 ) $ (110,170 ) $ (74,631 ) (1) Adjusted to reflect the adoption of ASC 606. See Note 2. The components of the provision for (benefit from) income taxes for the years ended January 31, 2019 , 2018 and 2017 are as follows (in thousands): Year Ended January 31, 2019 2018 2017 As Adjusted (1) As Adjusted (1) Current: Federal $ — $ — $ — State 61 — 18 Foreign 667 183 426 Total current provision for income taxes 728 183 444 Deferred: Federal (620 ) (32 ) 60 State (130 ) 10 6 Foreign 5 (482 ) (85 ) Total deferred provision for (benefit from) income taxes (745 ) (504 ) (19 ) Total provision for (benefit from) income taxes $ (17 ) $ (321 ) $ 425 (1) Adjusted to reflect the adoption of ASC 606. See Note 2. For the year ended January 31, 2019, the income tax benefit resulted from the release of valuation allowance in the United States in connection with the ScaleFT acquisition and excess tax benefits from stock-based compensation in the United Kingdom. The income tax benefit was partially offset by foreign income taxes, state taxes and tax amortization of goodwill. For the year ended January 31, 2018, the income tax benefit resulted from $1.3 million of excess tax deductions related to option exercises by foreign employees, a portion of which we used to claim a refund for taxes paid in prior years . For the year ended January 31, 2017, the income tax provision was related to foreign taxes and tax amortization of goodwill. The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate for the years ended January 31, 2019 , 2018 and 2017 : Year Ended January 31, 2019 2018 2017 As Adjusted (1) As Adjusted (1) Tax at federal statutory rate 21.0 % 33.8 % 34.0 % State income taxes, net of federal benefit 3.8 3.4 3.6 Change in valuation allowance (68.5 ) (27.1 ) (32.1 ) Stock-based compensation 45.5 42.4 (5.0 ) Tax Cuts and Jobs Act of 2017 — (51.3 ) — Other, net (1.8 ) (0.9 ) (1.1 ) Effective tax rate — % 0.3 % (0.6 )% (1) Adjusted to reflect the adoption of ASC 606. See Note 2. The tax effects of temporary differences and related deferred tax assets and liabilities as of January 31, 2019 and 2018 are as follows (in thousands): As of January 31, 2019 2018 As Adjusted (1) Deferred tax assets: Net operating loss carryforwards $ 202,471 $ 123,013 Stock-based compensation 13,185 7,926 Deferred revenue 1,312 213 Other reserves and accruals 13,113 3,084 Credits 791 791 Disallowed interest 1,769 — Total deferred tax assets 232,641 135,027 Valuation allowance (203,899 ) (116,948 ) Total deferred tax assets, net 28,742 18,079 Deferred tax liabilities: Deferred commissions (19,424 ) (14,597 ) Capitalized internal-use software costs (2,047 ) (2,389 ) Goodwill (217 ) (175 ) Depreciation and amortization (6,492 ) (441 ) Total deferred tax liabilities (28,180 ) (17,602 ) Net deferred tax assets (liabilities) $ 562 $ 477 (1) Adjusted to reflect the adoption of ASC 606. See Note 2. As a result of continuing losses, the Company has determined that it is not more likely than not that it will realize the benefits of the U.S. deferred tax assets and, therefore, the Company has recorded a valuation allowance to reduce the carrying value of the U.S. deferred tax assets, net of U.S. deferred tax liabilities, to approximately zero. The U.S. valuation allowance increased by $86.6 million and $18.6 million during the years ended January 31, 2019 and 2018 , respectively. As of January 31, 2019 , the Company had approximately $798.8 million of federal and $489.1 million of state net operating loss carryforwards available to offset future taxable income. If not utilized, the federal and state net operating loss carryforwards will begin to expire in 2029 and 2021, respectively. As of January 31, 2019, the Company had approximately $12.8 million of UK net operating losses which do not expire. As of January 31, 2019 , the Company had federal research and development tax credit carryforwards of $14.1 million and California research and development tax credit carryforwards of $9.8 million . The federal research and development credits will start to expire in 2030 while the California research and development credits do not expire. The Company has California Enterprise Zone credits of $1.0 million that begin to expire in 2023. The Company’s ability to utilize the net operating loss and tax credit carryforwards in the future may be subject to substantial restrictions in the event of past or future ownership changes as defined in Section 382 of the Internal Revenue Code and similar state tax laws. The Company attributes net revenue, costs and expenses to domestic and foreign components based on the terms of its agreements with its subsidiaries. The Company does not provide for federal income taxes on the undistributed earnings of its foreign subsidiaries as such earnings are to be reinvested offshore indefinitely. If the Company repatriated these earnings, the resulting income tax liability would be insignificant. The Company is subject to taxation in the United States and various states and foreign jurisdictions. On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (“Tax Act”) was signed into law making significant changes to the Internal Revenue Code. Changes include, but are not limited to, a corporate tax rate decrease to 21% effective for tax years beginning after December 31, 2017. This change in tax rate resulted in a reduction in the Company's net U.S. deferred tax assets before valuation allowance by $56.5 million , which was fully offset by a reduction in the Company's valuation allowance. The Tax Act provided for a one-time deemed mandatory repatriation of post-1986 undistributed foreign subsidiary earnings and profits, or E&P. The Company's final calculations show that it had negative undistributed foreign E&P and was not subject to the mandatory repatriation for the year ended January 31, 2018 . In December 2017, the SEC staff issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (SAB 118), which allowed the Company to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. As of January 31, 2019 , the Company has finalized all provisional amounts related to the Tax Act. Finalizing provisional adjustments related to the Tax Act did not have a material impact on the Company's consolidated financial statements as of January 31, 2019 . The Company expects further guidance may be forthcoming, which could result in additional impacts. A reconciliation of beginning and ending amount of unrecognized tax benefit is as follows (in thousands): Year Ended January 31, 2019 2018 2017 Gross amount of unrecognized tax benefits as of the beginning of the year $ 11,719 $ 5,775 $ 3,512 Additions based on tax positions related to a prior year 1,859 — — Additions based on tax positions related to current year 10,353 5,944 2,263 Gross amount of unrecognized tax benefits as of the end of the year $ 23,931 $ 11,719 $ 5,775 The material jurisdictions in which the Company is subject to potential examination include the United States, California, Australia, Canada and the United Kingdom. Due to the Company’s net operating loss carryforwards, all tax years since inception remain subject to examination by federal and California taxing authorities. For the United Kingdom, the Company recently closed an examination for fiscal 2016 with no adjustment, and is no longer subject to examinations for fiscal 2016 and prior. As of January 31, 2019 , 2018 and 2017, the Company had unrecognized tax benefits which would not impact the effective tax rate because of the valuation allowance. The Company's policy is to include interest and penalties related to unrecognized tax benefits within the provision for income taxes. The Company does not have any uncertain tax positions as of January 31, 2019 for which it is reasonably possible that the positions will increase or decrease within the next twelve months. As of January 31, 2019 and 2018 , the Company has no t accrued any interest or penalties related to unrecognized tax benefits.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Jan. 31, 2019
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share The Company computes net loss per share of common stock in conformity with the two-class method required for participating securities. The Company considers all series of Preferred Stock to be participating securities as the holders of the Preferred Stock are entitled to receive a non-cumulative dividend on a pari passu basis in the event that a dividend is paid on the common stock. The holders of the Preferred Stock do not have a contractual obligation to share in the Company’s losses. As such, the Company’s net losses for the years ended January 31, 2019 , 2018 and 2017 , were not allocated to these participating securities. Upon the closing of the IPO in April 2017, all shares of the Company’s then-outstanding redeemable convertible preferred stock automatically converted into the Company’s common stock. The following table presents the calculation of basic and diluted net loss per share for periods presented (dollars in thousands, except per share data): Year Ended January 31, 2019 2018 2017 Class A Class B Class A Class B Class A Class B Numerator: Net loss $ (107,926 ) $ (17,571 ) $ (31,980 ) $ (77,869 ) $ — $ (75,056 ) Denominator: Weighted-average shares outstanding, basic and diluted 92,452 15,052 24,165 58,839 — 19,038 Net loss per share attributable to common stockholders, basic and diluted $ (1.17 ) $ (1.17 ) $ (1.32 ) $ (1.32 ) $ — $ (3.94 ) The Company was in a loss position for all periods presented; accordingly, basic net loss per share is the same as diluted net loss per share as the inclusion of all potential common shares outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows (in thousands): Year Ended January 31, 2019 2018 2017 Unvested restricted common stock issued and outstanding 400 800 — Unvested RSUs issued and outstanding 4,836 2,863 — Unvested restricted stock awards issued and outstanding 388 599 — Shares committed under the ESPP 271 1,149 — Unvested shares subject to repurchase 48 188 — Conversion of convertible preferred stock — — 59,465 Shares related to convertible senior notes 7,134 — — Issued and outstanding stock options 17,804 24,917 32,866 Conversion of common stock warrant — — 188 Conversion of convertible Series B warrant — — 29 30,881 30,516 92,548 The Company expects to settle the principal amount of the 2023 Notes in cash, and therefore, the Company uses the treasury stock method for calculating any potential dilutive effect of the conversion option on diluted net income per share, if applicable. The conversion option will have a dilutive impact on net income per share of common stock when the average market price per share of the Company’s Class A common stock for a given period exceeds the conversion price of the 2023 Notes of $48.36 per share. During the year ended January 31, 2019 , the weighted average price per share of the Company’s Class A common stock exceeded the conversion price of the 2023 Notes; however, since the Company is in a net loss position there was no dilutive effect during any period presented.

Subsequent Events

Subsequent Events	12 Months Ended
	Jan. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On March 5, 2019, the Company entered into an agreement to acquire all issued and outstanding stock of Azuqua, Inc., a company which provides a no-code, cloud-based integration platform that automates workflows between applications and services, for total cash consideration of approximately $52.5 million . The acquisition will be accounted for under the acquisition method of accounting and is expected to close in the first quarter of fiscal 2020, subject to certain closing conditions. The Company has not completed its determination of total fair value of consideration transferred, assets acquired and liabilities assumed. The transaction is not expected to have a material impact on the consolidated financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Jan. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	The accompanying consolidated financial statements, which include the accounts of the Company and its wholly owned subsidiaries, have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP).
Principles of Consolidation	All intercompany balances and transactions have been eliminated in consolidation. Certain immaterial reclassifications of prior period amounts have been made in our consolidated balance sheets and consolidated statements of cash flows to conform to the current period presentation.
Fiscal Period	The Company’s fiscal year ends on January 31. References to fiscal 2019 , for example, refer to the fiscal year ended January 31, 2019 .
Use of Estimates	The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates, judgments and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. The Company bases its estimates on historical experience and on other assumptions that its management believes are reasonable under the circumstances. Actual results could vary from those estimates. The Company’s most significant estimates include the stand alone selling price (SSP) for each distinct performance obligation included in customer contracts with multiple performance obligations, the determination of the period of benefit for deferred commissions, the determination of the effective interest rate of the liability components of the 2023 Notes, determination of the fair value of the Company’s common stock prior to the completion of the IPO, the valuation of deferred income tax assets and contingencies and the valuation of acquired intangible assets.
Foreign Currency	The functional currencies of the Company’s foreign subsidiaries are the respective local currencies. Translation adjustments arising from the use of differing exchange rates from period to period are included in accumulated other comprehensive loss within the consolidated statements of redeemable convertible preferred stock and stockholders’ equity (deficit). Foreign currency transaction gains and losses are included in other expense, net in the consolidated statements of operations and were not material for the years ended January 31, 2019 , 2018 or 2017 . All assets and liabilities denominated in a foreign currency are translated into U.S. dollars at the exchange rate on the balance sheet date. Revenue and expenses are translated at the average exchange rate during the period, and equity balances are translated using historical exchange rates.
Segment Information	The Company operates in a single operating segment. The Company’s chief operating decision maker is its chief executive officer, who reviews financial information presented on a consolidated basis for purposes of making operating decisions, assessing financial performance and allocating resources.
Revenue Recognition, Cost of Revenue and Deferred Revenue	Deferred revenue consists of customer billings in advance of revenue being recognized from the Company’s subscription and support services and professional services arrangements. The Company primarily invoices its customers for its subscription services arrangements annually in advance. The Company’s payment terms generally provide that customers pay the invoiced portion of the total arrangement fee within 30 days of the invoice date. Amounts anticipated to be recognized within one year of the balance sheet date are recorded as deferred revenue, current; the remaining portion is recorded as deferred revenue, noncurrent in the consolidated balance sheets. The Company derives revenue from subscription fees (which include support fees) and professional services fees. The Company sells subscriptions to its platform through arrangements that are generally one to five years in length. The Company’s arrangements are generally noncancelable and nonrefundable. Furthermore, if a customer reduces the contracted usage or service level, the customer has no right of refund. The Company’s subscription arrangements do not provide customers with the right to take possession of the software supporting the platform and, as a result, are accounted for as service arrangements. This revenue recognition policy is consistent for sales generated directly with customers and sales generated indirectly through channel partners. The Company determines revenue recognition through the following steps: • Identification of the contract, or contracts, with a customer; • Identification of the performance obligations in the contract; • Determination of the transaction price; • Allocation of the transaction price to the performance obligations in the contract; and • Recognition of revenue when, or as, the Company satisfies a performance obligation. Subscription Revenue Subscription revenue, which includes support, is recognized on a straight-line basis over the noncancelable contractual term of the arrangement, generally beginning on the date that the Company’s service is made available to the customer. Professional Services Revenue The Company’s professional services principally consist of customer-specific requests for application integrations, user interface enhancements and other customer-specific requests. Revenue for the Company’s professional services is recognized as services are performed in proportion to their pattern of transfer. Contracts with Multiple Performance Obligations Some of the Company’s contracts with customers contain multiple performance obligations. For these contracts, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to the separate performance obligations on a relative SSP basis. The Company determines SSP based on observable, if available, prices for those related services when sold separately. When such observable prices are not available, the Company determines SSP based on overarching pricing objectives and strategies, taking into consideration market conditions and other factors, including customer size, volume purchased, market and industry conditions, product-specific factors and historical sales of the deliverables. Costs of revenue primarily consist of costs related to providing the Company’s cloud-based platform to its customers, including third-party hosting fees, amortization of capitalized internal-use software and finite-lived purchased developed technology, customer support, other employee-related expenses for security, technical operations and professional services staff, and allocated overhead costs.
Deferred Commissions	Sales commissions earned by the Company’s sales force are considered incremental and recoverable costs of obtaining a contract with a customer. Sales commissions for new revenue contracts, including incremental sales to existing customers, are deferred and then amortized on a straight-line basis over a period of benefit, which the Company has determined to be generally five years. The Company determined the period of benefit by taking into consideration its customer contracts, its technology and other factors. Sales commissions for renewal contracts (which are not considered commensurate with sales commissions for new revenue contracts and incremental sales to existing customers) are deferred and then amortized on a straight-line basis over the related period of benefit, which is generally the related contract renewal term. Amortization expense is included in sales and marketing expenses in the accompanying consolidated statements of operations.
Cash and Cash Equivalents	Cash and cash equivalents consist of cash on hand and highly liquid investments with original maturities of three months or less from the date of purchase. Cash equivalents generally consist of investments in money market funds. The fair market value of cash equivalents approximated their carrying value as of January 31, 2019 and 2018 .
Short-term Investments	The Company’s short-term investments comprise asset-backed securities, U.S. treasury securities and corporate debt securities. The Company determines the appropriate classification of its short-term investments at the time of purchase and reevaluates such designation at each balance sheet date. The Company has classified and accounted for its short-term investments as available-for-sale securities as the Company may sell these securities at any time for use in its current operations or for other purposes, even prior to maturity. As a result, the Company classifies its short-term investments, including securities with stated maturities beyond twelve months, within current assets in the consolidated balance sheets. Available-for-sale securities are recorded at fair value each reporting period. Unrealized gains and losses on these short-term investments are reported as a separate component of accumulated other comprehensive loss in the consolidated balance sheets until realized. Interest income is reported within other income (expense), net in the consolidated statements of operations. The Company periodically evaluates its short-term investments to assess whether those with unrealized loss positions are other-than-temporarily impaired. The Company considers various factors in determining whether to recognize an impairment charge, including the length of time the investment has been in a loss position, the extent to which the fair value is less than the Company’s cost basis, the investment’s financial condition and near-term prospects of the investee. Realized gains and losses are determined based on the specific identification method and are reported in other income (expense), net in the consolidated statements of operations. If the Company determines that the decline in an investment’s fair value is other-than-temporary, the difference is recognized as an impairment loss in the consolidated statements of operations.
Accounts Receivable and Allowances	Accounts receivable are recorded at the invoiced amount, net of allowances. These allowances are based on the Company’s assessment of the collectibility of accounts by considering the age of each outstanding invoice, the collection history of each customer and an evaluation of potential risk of loss associated with delinquent accounts. Amounts deemed uncollectible are recorded to these allowances in the consolidated balance sheets with an offsetting decrease in related deferred revenue and a charge to general and administrative expense in the consolidated statement of operations.
Property and Equipment	Property and equipment, net, is stated at cost less accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the respective assets. Repairs and maintenance costs are expensed as incurred. The useful lives of property and equipment are as follows: Useful lives Capitalized internal-use software costs 3 years Computers and equipment 3 years Furniture and fixtures 7 years Leasehold improvements Shorter of estimated useful life or remaining lease term
Capitalized Internal-Use Software Costs	The Company capitalizes as intangible assets certain costs incurred during the application development stage in connection with software development for its platform. Costs related to preliminary project activities and post-implementation activities are expensed as incurred. Capitalized costs are recorded as part of intangible assets. Maintenance and training costs are expensed as incurred. Capitalized internal-use software costs are amortized on a straight-line basis over the software’s estimated useful life, which is generally three years . The Company records amortization related to capitalized internal-use software within subscription cost of revenue in the consolidated statements of operations. The Company evaluates the useful lives of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets.
Business Combinations	When the Company acquires a business, the purchase price is allocated to the net tangible and identifiable intangible assets acquired. Any residual purchase price is recorded as goodwill. The allocation of the purchase price requires management to make estimates in determining the fair values of assets acquired and liabilities assumed, especially with respect to intangible assets. These estimates can include, but are not limited to, the cash flows that an asset is expected to generate in the future, the appropriate weighted-average cost of capital and the cost savings expected to be derived from acquiring an asset. These estimates are inherently uncertain and unpredictable. During the measurement period, which may be up to one year from the acquisition date, adjustments to the fair value of these tangible and intangible assets acquired and liabilities assumed may be recorded, with the corresponding offset to goodwill. Upon the conclusion of the measurement period or final determination of the fair value of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to the consolidated statements of operations.
Goodwill and Other Long-Lived Assets	The excess of the purchase price over the estimated fair value of net assets of businesses acquired in a business combination is recognized as goodwill. Goodwill is tested for impairment annually on November 1 st or more frequently if certain indicators are present. Long-lived assets, such as property and equipment and finite-lived intangible assets subject to amortization are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of any asset may not be recoverable. Recoverability of assets to be held and used is measured by comparing the carrying amount to the estimated undiscounted future cash flows expected to be generated. If the carrying amount exceeds the undiscounted cash flows, the assets are determined to be impaired and an impairment charge is recognized as the amount by which the carrying amount exceeds its fair value. The Company amortizes intangible assets with finite lives on a straight-line basis over their estimated useful lives in cost of revenue in the consolidated statements of operations.
Convertible Senior Notes	The 2023 Notes are accounted for in accordance with FASB ASC Subtopic 470‑20, Debt with Conversion and Other Options. Pursuant to ASC Subtopic 470‑20, issuers of certain convertible debt instruments, such as the 2023 Notes, that have a net settlement feature and may be settled wholly or partially in cash upon conversion are required to separately account for the liability (debt) and equity (conversion option) components of the instrument. The carrying amount of the liability component of the instrument is computed by estimating the fair value of a similar liability without the conversion option. The amount of the equity component is then calculated by deducting the fair value of the liability component from the principal amount of the instrument. The difference between the principal amount and the liability component represents a debt discount that is amortized to interest expense over the respective term of the 2023 Notes using the effective interest rate method. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. In accounting for the issuance costs related to the 2023 Notes, the allocation of issuance costs incurred between the liability and equity components was based on their relative values.
Advertising Expenses	Advertising costs are expensed as incurred. Advertising expense was $10.0 million , $9.4 million , and $4.4 million for the years ended January 31, 2019 , 2018 and 2017 .
Stock-Based Compensation	Stock-based compensation issued to employees and non-employees, including the purchase rights issued under the Company's 2017 Employee Stock Purchase Plan (ESPP), is measured based on the grant-date fair value of the awards and recognized as an expense following the straight-line attribution method over the requisite service period for stock options, restricted stock units (RSUs) and restricted stock, and over the offering period for the purchase rights issued under the ESPP. The Company’s use of the Black-Scholes option-pricing model to estimate the fair value of stock options granted requires the input of highly subjective assumptions. These assumptions and estimates are as follows: Fair value — Prior to the IPO, the Company's stock was not publicly traded and it estimated the fair value of common stock using various methodologies, including valuation analyses performed by third-party valuation firms. After the IPO, the Company used the publicly quoted price as reported on the Nasdaq Global Select Market as the fair value of its common stock. Expected volatility — Expected volatility is a measure of the amount by which the stock price is expected to fluctuate. Since the Company does not have sufficient trading history of its common stock, it estimates the expected volatility of its stock options at their grant date by taking the weighted-average historical volatility of a group of comparable publicly-traded companies over a period equal to the expected life of the options. Expected term — The Company determines the expected term based on the average period the stock options are expected to remain outstanding, generally calculated as the midpoint of the stock option’s vesting term and contractual expiration period, as the Company does not have sufficient historical information to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior. Risk-free rate — The Company uses the U.S. Treasury yield that corresponds with the expected term. Expected dividend yield — The Company utilizes a dividend yield of zero , as it does not currently issue dividends and does not expect to in the future.
Income Taxes	The Company accounts for income taxes in accordance with the liability method of accounting for income taxes. Under this method, the Company recognizes deferred tax assets and liabilities for the expected future tax consequences of temporary differences between the financial reporting and tax basis of assets and liabilities, as well as for operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates that are expected to apply to taxable income for the years in which those tax assets and liabilities are expected to be realized or settled. The Company records a valuation allowance to reduce its deferred tax assets to the net amount that the Company believes is more likely than not to be realized. In assessing the need for a valuation allowance, the Company has considered its historical levels of income, expectations of future taxable income and ongoing tax planning strategies. Because of the uncertainty of the realization of the deferred tax assets, the Company has recorded a full valuation allowance against its deferred tax assets. Realization of its deferred tax assets is dependent primarily upon future U.S. taxable income. The Company recognizes and measures tax benefits from uncertain tax positions using a two-step approach. The first step is to evaluate the tax position taken or expected to be taken by determining if the weight of available evidence indicates that it is more likely than not that the tax position will be sustained in an audit, including resolution of any related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement. Significant judgment is required to evaluate uncertain tax positions. Although the Company believes that it has adequately reserved for its uncertain tax positions, it can provide no assurance that the final tax outcome of these matters will not be materially different. The Company evaluates its uncertain tax position on a regular basis and evaluations are based on a number of factors, including changes in facts and circumstances, changes in tax law, correspondence with tax authorities during the course of an audit and effective settlement of audit issues. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will affect the provision for income taxes in the period in which such determination is made and could have a material impact on the Company’s financial condition and results of operations. The provision for income taxes includes the effects of any accruals that the Company believes are appropriate, as well as the related net interest and penalties.
Facility Leases	Certain facility lease agreements contain rent holidays, allowances and rent escalation provisions. For these leases, the Company recognizes the related rental expense on a straight-line basis over the lease period of the facility and records the difference between amounts charged to operations and amounts paid as deferred rent. These rent holidays, allowances and rent escalations are considered in determining the straight-line expense to be recorded over the lease term.
Concentrations of Risk and Significant Customers	The Company’s financial instruments that are exposed to concentrations of credit risk consist primarily of cash and cash equivalents, short-term investments and accounts receivable. Cash and cash equivalents and short-term investments are currently held in two financial institutions and, at times, may exceed federally insured limits. As of January 31, 2019 and 2018 and for each of the three years ended January 31, 2019 , no single customer represented greater than 10% of accounts receivable or greater than 10% of revenue, respectively. In order to reduce the risk of downtime of the Company’s subscription services, the Company utilizes data center facilities operated by third parties located in Virginia, Oregon, Germany and Ireland. The Company has internal procedures to restore services in the event of disaster at any of its current data center facilities. Even with these procedures for disaster recovery in place, the Company’s subscription services could be significantly interrupted during the time period following a disaster at one of its sites and the subsequent restoration of services at another site. Other than the United States, no individual country exceeded 10% of total revenue for the years ended January 31, 2019 , 2018 and 2017 . Property and equipment by geographic location is based on the location of the legal entity that owns the asset. As of January 31, 2019 and 2018 , substantially all of the Company’s property and equipment was located in the United States.
Net Loss per Share	The Company computes basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method required for participating securities. Under the two-class method, basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase, without consideration for potentially dilutive securities as they do not share in losses. The diluted net loss per share attributable to common stockholders is computed giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, options to purchase common stock, unvested RSUs, purchase rights issued under the ESPP, shares subject to repurchase from early exercised options, unvested common stock and restricted stock issued in connection with certain business combinations, convertible senior notes and warrants are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as the effect is antidilutive. Since the Company's IPO, Class A and Class B common stock are the only outstanding equity of the Company. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion rights. See Note 14.
Recently Adopted and Not Yet Adopted Accounting Pronouncements	In May 2014, the Financial Accounting Standards Board (FASB) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). Topic 606 supersedes the revenue recognition requirements in Accounting Standards Codification (ASC) Topic 605, Revenue Recognition (Topic 605), and requires the recognition of revenue when promised goods or services are transferred to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. Topic 606 also includes Subtopic 340-40, Other Assets and Deferred Costs - Contracts with Customers, which requires the deferral of incremental costs of obtaining a contract with a customer. Collectively, the Company refers to Topic 606 and Subtopic 340-40 as "ASC 606." The Company adopted the requirements of ASC 606 as of February 1, 2018, utilizing the full retrospective method of transition. Adoption of ASC 606 resulted in changes to the Company’s accounting policies for revenue recognition and deferred commissions as detailed below. The Company applied ASC 606 using a practical expedient where the consideration allocated to the remaining performance obligations and an explanation of when the Company expects to recognize that amount as revenue for all reporting periods presented before the date of the initial application is not disclosed. The impact of adopting ASC 606 on fiscal 2018 and 2017 revenue is not material. The primary impact of adopting ASC 606 relates to the deferral of incremental costs of obtaining contracts, primarily consisting of sales commissions. Under Topic 605, the Company deferred only direct and incremental commission costs to obtain a contract and amortized those costs on a straight-line basis over the term of the related contract, which was generally one to three years . Under ASC 606, the Company defers all incremental commission costs to obtain the contract. The Company amortizes these costs on a straight-line basis over a period of benefit, determined to be generally five years or the related contractual renewal term. The Company adjusted its consolidated financial statements from amounts previously reported due to the adoption of ASC 606. Select consolidated statement of operations line items, which reflect the adoption of ASC 606, are as follows (in thousands except per share data): Year Ended January 31, 2018 2017 As Reported Adoption of ASU 2014-09 As Adjusted As Reported Adoption of ASU 2014-09 As Adjusted Revenue Subscription $ 239,177 $ (2,755 ) $ 236,422 $ 143,136 $ 1,773 $ 144,909 Professional services and other 20,813 (688 ) 20,125 17,190 (1,293 ) 15,897 Total revenue 259,990 (3,443 ) 256,547 160,326 480 160,806 Sales and marketing 172,973 (7,953 ) 165,020 118,742 (7,973 ) 110,769 Total operating expenses 295,597 (7,953 ) 287,644 187,500 (7,973 ) 179,527 Net loss (114,359 ) 4,510 (109,849 ) (83,509 ) 8,453 (75,056 ) Net loss per share, basic and diluted $ (1.38 ) $ 0.06 $ (1.32 ) $ (4.39 ) $ 0.45 $ (3.94 ) Select consolidated balance sheet line items, which reflect the adoption of ASC 606, are as follows (in thousands): As of January 31, 2018 As Reported Adoption of ASU 2014-09 As Adjusted Assets Current assets: Deferred commissions $ 16,481 $ 1,274 $ 17,755 Prepaid expenses and other current assets 16,973 808 17,781 Total current assets 315,416 2,082 317,498 Deferred commissions, noncurrent 10,971 29,784 40,755 Total assets $ 367,397 $ 31,866 $ 399,263 Liabilities and stockholders’ equity Deferred revenue $ 162,633 $ (2,817 ) $ 159,816 Total current liabilities 190,760 (2,817 ) 187,943 Deferred revenue, noncurrent 6,034 (1,071 ) 4,963 Total liabilities 203,811 (3,888 ) 199,923 Accumulated deficit (402,468 ) 35,754 (366,714 ) Total stockholders’ equity $ 163,586 $ 35,754 $ 199,340 The adoption of ASC 606 had no impact on cash provided by or used in operating, investing, or financing activities in the Company’s consolidated statement of cash flows. Additionally, the adoption of ASC 606 did not have a material impact on the provision for (benefit from) income taxes. The adoption adjustments impacted the deferred income taxes pertaining to the U.S. entity which are subject to a full valuation allowance. In February 2018, the FASB issued ASU No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (ASU 2018-02). Under existing U.S. GAAP, the effects of changes in tax rates and laws on deferred tax balances are recorded as a component of income tax expense in the period in which the law was enacted. When deferred tax balances related to items originally recorded in accumulated other comprehensive income (loss) are adjusted, certain tax effects become stranded in accumulated other comprehensive income. The amendments in ASU 2018-02 allow a reclassification from accumulated other comprehensive income (loss) to retained earnings (accumulated deficit) for stranded income tax effects resulting from the 2017 Tax Cuts and Jobs Act. The amendments in this ASU also require certain disclosures about stranded income tax effects. The guidance is effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption in any period is permitted. The Company’s provisional adjustments recorded in fiscal 2018 to account for the impact of the 2017 Tax Cuts and Jobs Act did not result in stranded tax effects. The early adoption of this standard did not have a material impact on the Company’s consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07, Compensation - Stock Compensation (Topic 718) Improvements to Non-Employee Share Based Payment Accounting (ASU 2018-07), with an intent to reduce cost and complexity and to improve financial reporting for share-based payments issued to non-employees. The amendments in ASU 2018-07 provide for the simplification of the measurement of share-based payment transactions for acquiring goods and services from non-employees. This standard expands the scope of Topic 718 to include share-based payments issued to non-employees for goods or services, aligning the accounting for share-based payments to non-employees and employees. This guidance is effective for annual and interim periods beginning after December 15, 2018, and early adoption is permitted. The early adoption of this standard did not have a material impact on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (ASU 2018-13), which amends ASC 820, Fair Value Measurement. ASU 2018-13 modifies the disclosure requirements for fair value measurements by removing, modifying or adding certain disclosures. This guidance is effective for the Company on February 1, 2020, with early adoption permitted for the removal and modification of disclosures and delayed adoption until February 1, 2020 permitted for the new disclosures. The removed and modified disclosures have been adopted on a retrospective basis, and the new disclosures have been adopted on a prospective basis. The early adoption of this standard did not have a material impact on the Company’s consolidated financial statements. Recent Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02 (Topic 842), Leases (ASU 2016-02), which supersedes the guidance in topic ASC 840, Leases. The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. This classification will determine whether lease expense is recognized based on an effective interest method or on a straight-line basis over the term of the lease. A lessee is also required to record a right-of-use asset (ROU) and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The Company will be required to recognize and measure leases existing at, or entered into after, the beginning of the earliest comparative period presented using a modified retrospective approach, with certain practical expedients available. ASU 2016-02 is effective for the Company beginning February 1, 2019. The Company expects to elect the available practical expedients on adoption. The Company is assessing the impact of ASU 2016-02 on its internal controls over financial reporting. Adoption of ASU 2016-02 will have a material impact on the Company's consolidated balance sheets, but will not have a material impact on the Company's consolidated income statements and taxes. The most significant impact will be the recognition of ROU assets and lease liabilities for operating leases. The Company expects adoption of the standard will result in the recognition of additional ROU assets and lease liabilities for operating leases in the range of approximately $121 million to $126 million , and $158 million to $163 million , respectively, as of January 31, 2019 . Additionally, the adoption of this standard will have no impact to cash provided by or used in operating, financing, or investing activities on the Company's consolidated cash flows statements. In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (ASU 2018-15), which requires a customer in a cloud computing arrangement that is a service contract to follow the internal-use software guidance in Accounting Standards Codification 350-40 to determine which implementation costs to defer and recognize as an asset. This guidance is effective for the Company on February 1, 2020 with early adoption permitted. The Company is currently evaluating the impact of the adoption of this standard on its consolidated financial statements.
Fair Value Measurement	The Company measures its financial assets at fair value each reporting period using a fair value hierarchy that prioritizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure as follows: Level 1-Valuations based on observable inputs that reflect quoted prices for identical assets or liabilities in active markets. Level 2-Valuations based on other inputs that are directly or indirectly observable in the marketplace. Level 3-Valuations based on unobservable inputs that are supported by little or no market activity.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Jan. 31, 2019
Accounting Policies [Abstract]
Schedule of Property Plant and Equipment Estimated Useful Life	The useful lives of property and equipment are as follows: Useful lives Capitalized internal-use software costs 3 years Computers and equipment 3 years Furniture and fixtures 7 years Leasehold improvements Shorter of estimated useful life or remaining lease term Property and equipment consisted of the following (in thousands): As of January 31, 2019 2018 Computers and equipment $ 3,668 $ 5,384 Furniture and fixtures 11,012 7,083 Leasehold improvements 47,883 8,188 Property and equipment, gross 62,563 20,655 Less accumulated depreciation (9,642 ) (8,115 ) Property and equipment, net $ 52,921 $ 12,540
Schedule of Revenue by Geographic Area	The following table sets forth revenue by geographic area (in thousands): Year Ended January 31, 2019 2018 2017 United States $ 337,367 $ 217,300 $ 135,364 International 61,887 39,247 25,442 Total $ 399,254 $ 256,547 $ 160,806
Schedule of Impact of New Accounting Pronouncements	Select consolidated statement of operations line items, which reflect the adoption of ASC 606, are as follows (in thousands except per share data): Year Ended January 31, 2018 2017 As Reported Adoption of ASU 2014-09 As Adjusted As Reported Adoption of ASU 2014-09 As Adjusted Revenue Subscription $ 239,177 $ (2,755 ) $ 236,422 $ 143,136 $ 1,773 $ 144,909 Professional services and other 20,813 (688 ) 20,125 17,190 (1,293 ) 15,897 Total revenue 259,990 (3,443 ) 256,547 160,326 480 160,806 Sales and marketing 172,973 (7,953 ) 165,020 118,742 (7,973 ) 110,769 Total operating expenses 295,597 (7,953 ) 287,644 187,500 (7,973 ) 179,527 Net loss (114,359 ) 4,510 (109,849 ) (83,509 ) 8,453 (75,056 ) Net loss per share, basic and diluted $ (1.38 ) $ 0.06 $ (1.32 ) $ (4.39 ) $ 0.45 $ (3.94 ) Select consolidated balance sheet line items, which reflect the adoption of ASC 606, are as follows (in thousands): As of January 31, 2018 As Reported Adoption of ASU 2014-09 As Adjusted Assets Current assets: Deferred commissions $ 16,481 $ 1,274 $ 17,755 Prepaid expenses and other current assets 16,973 808 17,781 Total current assets 315,416 2,082 317,498 Deferred commissions, noncurrent 10,971 29,784 40,755 Total assets $ 367,397 $ 31,866 $ 399,263 Liabilities and stockholders’ equity Deferred revenue $ 162,633 $ (2,817 ) $ 159,816 Total current liabilities 190,760 (2,817 ) 187,943 Deferred revenue, noncurrent 6,034 (1,071 ) 4,963 Total liabilities 203,811 (3,888 ) 199,923 Accumulated deficit (402,468 ) 35,754 (366,714 ) Total stockholders’ equity $ 163,586 $ 35,754 $ 199,340

Cash Equivalents and Short-te_2

Cash Equivalents and Short-term Investments (Tables)	12 Months Ended
	Jan. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Schedule of Amortized Costs, Unrealized Gains and Losses and Estimated Fair Value of Cash Equivalents and Short-term Investments	The amortized costs, unrealized gains and losses and estimated fair values of the Company’s cash equivalents and short-term investments as of January 31, 2019 and 2018 were as follows (in thousands): As of January 31, 2019 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Cash equivalents: Money market funds $ 247,426 $ — $ — $ 247,426 Corporate debt securities 3,409 — (1 ) 3,408 Total cash equivalents 250,835 — (1 ) 250,834 Short-term investments: U.S. treasury securities 195,913 37 (53 ) 195,897 Corporate debt securities 69,483 13 (19 ) 69,477 Total short-term investments 265,396 50 (72 ) 265,374 Total $ 516,231 $ 50 $ (73 ) $ 516,208 As of January 31, 2018 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Cash equivalents: Money market funds $ 90,770 $ — $ — $ 90,770 Total cash equivalents 90,770 — — 90,770 Short-term investments: Commercial paper 15,946 — — 15,946 U.S. treasury securities 61,896 — (158 ) 61,738 Corporate debt securities 24,125 — (44 ) 24,081 Total short-term investments 101,967 — (202 ) 101,765 Total $ 192,737 $ — $ (202 ) $ 192,535
Schedule of Contractual Maturities of Short-term Investments	The following tables present the contractual maturities of the Company’s short-term investments as of January 31, 2019 and 2018 (in thousands): As of January 31, 2019 As of January 31, 2018 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Due within one year $ 265,396 $ 265,374 $ 93,421 $ 93,237 Due between one to five years — — 8,546 8,528 Total $ 265,396 $ 265,374 $ 101,967 $ 101,765

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Jan. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table presents information about the Company’s financial assets that are measured at fair value on a recurring basis using the above input categories (in thousands): As of January 31, 2019 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 247,426 $ — $ — $ 247,426 Corporate debt securities — 3,408 — 3,408 Total cash equivalents 247,426 3,408 — 250,834 Short-term investments: U.S. treasury securities — 195,897 — 195,897 Corporate debt securities — 69,477 — 69,477 Total short-term investments — 265,374 — 265,374 Total cash equivalents and short-term investments $ 247,426 $ 268,782 $ — $ 516,208 As of January 31, 2018 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 90,770 $ — $ — $ 90,770 Total cash equivalents 90,770 — — 90,770 Short-term investments: Commercial paper — 15,946 — $ 15,946 U.S. treasury securities — 61,738 — $ 61,738 Corporate debt securities — 24,081 — 24,081 Total short-term investments — 101,765 — 101,765 Total cash equivalents and short-term investments $ 90,770 $ 101,765 $ — $ 192,535
Schedule of Carrying Amounts and Estimated Fair Values of Convertible Note	The following table presents the carrying amounts and estimated fair values of our financial instruments that are not recorded at fair value on the consolidated balance sheets (in thousands): As of January 31, 2019 Net Carrying Amount Estimated Convertible senior notes $ 278,231 $ 620,565

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, net (Tables)	12 Months Ended
	Jan. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	Goodwill balances as of January 31, 2019 and 2018 were as follows (in thousands): Balance at January 31, 2018 $ 6,282 Goodwill recorded in connection with ScaleFT acquisition 11,807 Balance at January 31, 2019 $ 18,089
Schedule of Intangible Assets, net	Intangible assets consisted of the following (in thousands): As of January 31, 2019 Gross Accumulated Amortization Write-offs Net Capitalized internal-use software costs $ 19,838 $ (9,969 ) $ — $ 9,869 Purchased developed technology 4,600 (833 ) — 3,767 Software licenses 1,023 (763 ) — 260 $ 25,461 $ (11,565 ) $ — $ 13,896 As of January 31, 2018 Gross Accumulated Amortization Write-offs Net Capitalized internal-use software costs $ 17,511 $ (5,172 ) $ (1,077 ) $ 11,262 Software licenses 1,094 (558 ) (37 ) 499 $ 18,605 $ (5,730 ) $ (1,114 ) $ 11,761
Schedule of Estimated Remaining Amortization Expense for Intangible Assets	As of January 31, 2019 , estimated remaining amortization expense for the intangible assets by fiscal year is as follows (in thousands): 2020 6,302 2021 4,789 2022 1,459 2023 1,346 Total $ 13,896

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Jan. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Property and Equipment, net	The useful lives of property and equipment are as follows: Useful lives Capitalized internal-use software costs 3 years Computers and equipment 3 years Furniture and fixtures 7 years Leasehold improvements Shorter of estimated useful life or remaining lease term Property and equipment consisted of the following (in thousands): As of January 31, 2019 2018 Computers and equipment $ 3,668 $ 5,384 Furniture and fixtures 11,012 7,083 Leasehold improvements 47,883 8,188 Property and equipment, gross 62,563 20,655 Less accumulated depreciation (9,642 ) (8,115 ) Property and equipment, net $ 52,921 $ 12,540
Schedule of Allowances	The Company’s allowances for the years ended January 31, 2019 , 2018 and 2017 are as follows (in thousands): As of January 31, 2019 2018 2017 Balance, beginning of period $ 1,472 $ 1,306 $ 861 Additions 888 431 1,185 Write-offs (262 ) (265 ) (740 ) Balance, end of period $ 2,098 $ 1,472 $ 1,306
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): As of January 31, 2019 2018 Deposit related to early exercise of unvested options $ 370 $ 1,119 Accrued expenses 6,392 3,389 Accrued taxes payable 1,195 835 Deferred rent, current 2,002 520 Other — 324 Accrued expenses and other current liabilities $ 9,959 $ 6,187
Schedule of Other Liabilities, noncurrent	Other liabilities, noncurrent consisted of the following (in thousands): As of January 31, 2019 2018 Deferred rent, noncurrent $ 35,980 $ 5,010 Deferred tax liabilities 727 175 Other 2,292 1,832 Other liabilities, noncurrent $ 38,999 $ 7,017

Debt and Financing Arrangemen_2

Debt and Financing Arrangements (Tables)	12 Months Ended
	Jan. 31, 2019
Debt Disclosure [Abstract]
Schedule of Interest Expense	The following table sets forth total interest expense recognized related to the 2023 Notes (in thousands): Year Ended January 31, 2019 Contractual interest expense $ 793 Amortization of debt issuance costs 1,085 Amortization of debt discount 13,194 Total $ 15,072
Schedule of Liability and Equity Component of 2023 Notes	The 2023 Notes, net consisted of the following (in thousands): As of January 31, 2019 Liability component: Principal $ 345,000 Less: unamortized debt issuance costs and debt discount (73,372 ) Net carrying amount $ 271,628 Equity component: 2023 Notes $ 79,962 Less: issuance costs (2,320 ) Carrying amount of the equity component (1) $ 77,642 (1) Included in the consolidated balance sheets within Additional paid-in capital.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Jan. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	As of January 31, 2019 , the future minimum lease payments by fiscal year under various operating leases and purchase obligations, such as data center operations and sales and marketing activities, are as follows (in thousands): Operating Purchase Obligations Total 2020 $ 16,672 $ 19,668 $ 36,340 2021 26,606 15,101 41,707 2022 28,138 15,101 43,239 2023 27,777 10,000 37,777 2024 28,384 — 28,384 Thereafter 117,101 — 117,101 Total contractual obligations $ 244,678 $ 59,870 $ 304,548
Schedule of Purchase Obligations Fiscal Maturity Schedule	As of January 31, 2019 , the future minimum lease payments by fiscal year under various operating leases and purchase obligations, such as data center operations and sales and marketing activities, are as follows (in thousands): Operating Purchase Obligations Total 2020 $ 16,672 $ 19,668 $ 36,340 2021 26,606 15,101 41,707 2022 28,138 15,101 43,239 2023 27,777 10,000 37,777 2024 28,384 — 28,384 Thereafter 117,101 — 117,101 Total contractual obligations $ 244,678 $ 59,870 $ 304,548

Common Stock and Stockholders_2

Common Stock and Stockholders' Equity (Tables)	12 Months Ended
	Jan. 31, 2019
Equity [Abstract]
Schedule of Common Stock Reserved for Future Issuance	As of January 31, 2019 , shares of common stock reserved for future issuance are as follows: Options and unvested RSUs outstanding 22,639,330 Available for future stock option and RSU grants 12,635,830 Available for ESPP 2,855,127 38,130,287

Employee Incentive Plans (Table

Employee Incentive Plans (Tables)	12 Months Ended
	Jan. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Stock-based Compensation Expense by Award Type	Stock-based compensation expense by award type was as follows (in thousands): Year Ended January 31, 2019 2018 2017 Stock options $ 23,466 $ 24,186 $ 17,127 RSUs 41,637 9,104 — ESPP 7,248 7,111 — Restricted stock awards 1,608 3,281 — Restricted common stock 2,361 6,178 — Total $ 76,320 $ 49,860 $ 17,127
Schedule of Stock-based Compensation Expense by Statement of Operations Location	Stock-based compensation expense was recorded in the following cost and expense categories in the Company’s consolidated statements of operations (in thousands): Year Ended January 31, 2019 2018 2017 Cost of revenue: Subscription $ 7,837 $ 4,600 $ 1,979 Professional services and other 4,983 3,137 1,283 Research and development 22,642 18,107 2,992 Sales and marketing 22,916 13,242 6,029 General and administrative 17,942 10,774 4,844 Total $ 76,320 $ 49,860 $ 17,127
Schedule of Stock Option Activity	A summary of the Company’s stock option activity and related information is as follows: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding as of January 31, 2018 24,917,045 $ 7.37 7.6 $ 550,173 Granted 684,500 39.21 Exercised (6,576,700 ) 5.61 Canceled (1,221,051 ) 8.55 Outstanding as of January 31, 2019 17,803,794 $ 9.16 7.1 $ 1,304,446 As of January 31, 2019: Vested and expected to vest 17,803,794 $ 9.16 7.1 $ 1,304,446 Vested and exercisable 9,681,494 $ 6.82 6.6 $ 731,998
Schedule of Black-Scholes Option Pricing Model Estimated Fair Value Assumptions	The Company used the Black-Scholes option pricing model to estimate the fair value of stock options granted with the following assumptions: Year Ended January 31, 2019 2018 2017 Expected volatility 40 % 40% - 41% 40% - 44% Expected term (in years) 6.3 6.3 - 6.4 5.5 - 6.9 Risk-free interest rate 2.70 % 1.87% - 2.21% 1.13% - 2.28% Expected dividend yield — — —
Schedule of Nonvested Restricted Stock Units Activity	A summary of the Company’s RSU activities and related information is as follows: Number of Weighted- Outstanding as of January 31, 2018 2,862,929 $ 24.38 Granted 3,392,285 54.34 Vested (976,248 ) 23.92 Forfeited (443,430 ) 35.22 Outstanding as of January 31, 2019 4,835,536 $ 44.49
Schedule of ESPP Black-Scholes Option Pricing Model Estimated Fair Value Assumptions	The Company estimated the fair value of ESPP purchase rights using a Black-Scholes option pricing model with the following assumptions: Year Ended January 31, 2019 2018 Expected volatility 39% - 70% 32% - 38% Expected term (in years) 0.5 - 1.0 0.5 - 1.2 Risk-free interest rate 2.12% - 2.62% 0.95% - 1.73% Expected dividend yield — —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Jan. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Domestic and Foreign Components of Pre-tax Loss	The domestic and foreign components of pre-tax loss for the years ended January 31, 2019 , 2018 and 2017 are as follows (in thousands): Year Ended January 31, 2019 2018 2017 As Adjusted (1) As Adjusted (1) Domestic $ (128,214 ) $ (112,858 ) $ (76,485 ) Foreign 2,700 2,688 1,854 Loss before provision for (benefit from) income taxes $ (125,514 ) $ (110,170 ) $ (74,631 ) (1) Adjusted to reflect the adoption of ASC 606. See Note 2.
Schedule of Components of Provision for (Benefit from) Income Taxes	The components of the provision for (benefit from) income taxes for the years ended January 31, 2019 , 2018 and 2017 are as follows (in thousands): Year Ended January 31, 2019 2018 2017 As Adjusted (1) As Adjusted (1) Current: Federal $ — $ — $ — State 61 — 18 Foreign 667 183 426 Total current provision for income taxes 728 183 444 Deferred: Federal (620 ) (32 ) 60 State (130 ) 10 6 Foreign 5 (482 ) (85 ) Total deferred provision for (benefit from) income taxes (745 ) (504 ) (19 ) Total provision for (benefit from) income taxes $ (17 ) $ (321 ) $ 425 (1) Adjusted to reflect the adoption of ASC 606. See Note 2.
Schedule of Effective Income Tax Rate Reconciliation	The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate for the years ended January 31, 2019 , 2018 and 2017 : Year Ended January 31, 2019 2018 2017 As Adjusted (1) As Adjusted (1) Tax at federal statutory rate 21.0 % 33.8 % 34.0 % State income taxes, net of federal benefit 3.8 3.4 3.6 Change in valuation allowance (68.5 ) (27.1 ) (32.1 ) Stock-based compensation 45.5 42.4 (5.0 ) Tax Cuts and Jobs Act of 2017 — (51.3 ) — Other, net (1.8 ) (0.9 ) (1.1 ) Effective tax rate — % 0.3 % (0.6 )% (1) Adjusted to reflect the adoption of ASC 606. See Note 2.
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences and related deferred tax assets and liabilities as of January 31, 2019 and 2018 are as follows (in thousands): As of January 31, 2019 2018 As Adjusted (1) Deferred tax assets: Net operating loss carryforwards $ 202,471 $ 123,013 Stock-based compensation 13,185 7,926 Deferred revenue 1,312 213 Other reserves and accruals 13,113 3,084 Credits 791 791 Disallowed interest 1,769 — Total deferred tax assets 232,641 135,027 Valuation allowance (203,899 ) (116,948 ) Total deferred tax assets, net 28,742 18,079 Deferred tax liabilities: Deferred commissions (19,424 ) (14,597 ) Capitalized internal-use software costs (2,047 ) (2,389 ) Goodwill (217 ) (175 ) Depreciation and amortization (6,492 ) (441 ) Total deferred tax liabilities (28,180 ) (17,602 ) Net deferred tax assets (liabilities) $ 562 $ 477 (1) Adjusted to reflect the adoption of ASC 606. See Note 2.
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of beginning and ending amount of unrecognized tax benefit is as follows (in thousands): Year Ended January 31, 2019 2018 2017 Gross amount of unrecognized tax benefits as of the beginning of the year $ 11,719 $ 5,775 $ 3,512 Additions based on tax positions related to a prior year 1,859 — — Additions based on tax positions related to current year 10,353 5,944 2,263 Gross amount of unrecognized tax benefits as of the end of the year $ 23,931 $ 11,719 $ 5,775

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Jan. 31, 2019
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share	The following table presents the calculation of basic and diluted net loss per share for periods presented (dollars in thousands, except per share data): Year Ended January 31, 2019 2018 2017 Class A Class B Class A Class B Class A Class B Numerator: Net loss $ (107,926 ) $ (17,571 ) $ (31,980 ) $ (77,869 ) $ — $ (75,056 ) Denominator: Weighted-average shares outstanding, basic and diluted 92,452 15,052 24,165 58,839 — 19,038 Net loss per share attributable to common stockholders, basic and diluted $ (1.17 ) $ (1.17 ) $ (1.32 ) $ (1.32 ) $ — $ (3.94 )
Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Per Share	Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows (in thousands): Year Ended January 31, 2019 2018 2017 Unvested restricted common stock issued and outstanding 400 800 — Unvested RSUs issued and outstanding 4,836 2,863 — Unvested restricted stock awards issued and outstanding 388 599 — Shares committed under the ESPP 271 1,149 — Unvested shares subject to repurchase 48 188 — Conversion of convertible preferred stock — — 59,465 Shares related to convertible senior notes 7,134 — — Issued and outstanding stock options 17,804 24,917 32,866 Conversion of common stock warrant — — 188 Conversion of convertible Series B warrant — — 29 30,881 30,516 92,548

Overview and Basis of Present_2

Overview and Basis of Presentation - Narrative (Details) - USD ($)	Feb. 23, 2018	Apr. 07, 2017	Apr. 06, 2017	Jan. 31, 2019	Jan. 31, 2018	[1]	Jan. 31, 2017	[1]
Class of Stock [Line Items]
Initial public offering costs				$ 0	$ 4,038,000		$ 1,584,000
Class A Common Stock
Class of Stock [Line Items]
Price per share in initial public offering (in dollars per share)		$ 17
Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Redeemable convertible preferred stock converted to common class B stock (in shares)			59,491,640
Class B Common Stock
Class of Stock [Line Items]
Common class B stock after conversion of redeemable convertible stock (in shares)			59,491,640
Initial Public Offering
Class of Stock [Line Items]
Proceeds from initial public offering, net of underwriters' discounts and commissions		$ 200,000,000
Initial public offering costs		$ 5,600,000
Initial Public Offering | Class A Common Stock
Class of Stock [Line Items]
Shares issued in initial public offering (in shares)		12,650,000
Senior Notes | Convertible Senior Notes Due 2023
Class of Stock [Line Items]
Aggregate principal amount	$ 345,000,000
Fixed interest rate	0.25%
Proceeds from issuance of debt	$ 345,000,000
Debt issuance costs	$ 10,000,000
[1]	See Note 2 for a summary of adjustments.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017	Feb. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Payment terms for deferred revenue	30 days
Amortization period for capitalized contract costs	5 years
Commissions capitalized as contract costs	$ 41,300,000	$ 27,000,000
Amortization of contract costs	20,900,000	15,200,000	$ 10,500,000
Impairment loss related to costs capitalized	0	0
Noncurrent portion of restricted cash	11,400,000	8,300,000
Advertising expenses	$ 10,000,000	$ 9,400,000	$ 4,400,000
ESPP
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Expected dividend yield	0.00%	0.00%
Capitalized internal-use software costs
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible asset, useful life	3 years
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract duration	1 year
Amortization period for capitalized contract costs	1 year
Minimum | Accounting Standards Update 2016-02 | Scenario, Forecast
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets, operating leases				$ 121,000,000
Operating lease liability				158,000,000
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Contract duration	5 years
Amortization period for capitalized contract costs	3 years
Maximum | Accounting Standards Update 2016-02 | Scenario, Forecast
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets, operating leases				126,000,000
Operating lease liability				$ 163,000,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives (Details)	12 Months Ended
	Jan. 31, 2019
Computers and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	7 years
Capitalized internal-use software costs
Property, Plant and Equipment [Line Items]
Intangible asset, useful life	3 years

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Revenue by Geographic Area (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 399,254	$ 256,547	[1]	$ 160,806	[1]
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	337,367	217,300		135,364
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 61,887	$ 39,247		$ 25,442
[1]	See Note 2 for a summary of adjustments.

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Schedule of Impact of New Accounting Pronouncements (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017		Jan. 31, 2016
Revenue
Total revenue		$ 399,254	$ 256,547	[1]	$ 160,806	[1]
Sales and marketing		227,960	165,020	[1]	110,769	[1]
Total operating expenses		405,455	287,644	[1]	179,527	[1]
Net loss	[2]	$ (125,497)	$ (109,849)	[1],[3],[4]	$ (75,056)	[1],[3],[4]
Net loss per share, basic and diluted (in dollars per share)		$ (1.17)	$ (1.32)		$ (3.94)	[1]
Current assets:
Deferred commissions		$ 24,185	$ 17,755	[5]
Prepaid expenses and other current assets		29,451	17,781	[5]
Total current assets		709,330	317,498	[5]
Deferred commissions, noncurrent		54,812	40,755	[5]
Total assets		864,335	399,263	[5]
Liabilities and stockholders’ equity
Deferred revenue		245,622	159,816	[5]
Total current liabilities		564,191	187,943	[5]
Deferred revenue, noncurrent		8,768	4,963	[5]
Total liabilities		611,958	199,923	[5]
Accumulated deficit		(492,211)	(366,714)	[5]
Total stockholders’ equity	[2]	252,377	199,340	[5]	$ (212,361)		$ (158,271)
As Reported
Revenue
Total revenue			259,990		160,326
Sales and marketing			172,973		118,742
Total operating expenses			295,597		187,500
Net loss			$ (114,359)		$ (83,509)
Net loss per share, basic and diluted (in dollars per share)			$ (1.38)		$ (4.39)
Current assets:
Deferred commissions			$ 16,481
Prepaid expenses and other current assets			16,973
Total current assets			315,416
Deferred commissions, noncurrent			10,971
Total assets			367,397
Liabilities and stockholders’ equity
Deferred revenue			162,633
Total current liabilities			190,760
Deferred revenue, noncurrent			6,034
Total liabilities			203,811
Accumulated deficit			(402,468)
Total stockholders’ equity			163,586
Adoption of ASU 2014-09 | Accounting Standards Update 2014-09
Revenue
Total revenue			(3,443)		$ 480
Sales and marketing			(7,953)		(7,973)
Total operating expenses			(7,953)		(7,973)
Net loss			$ 4,510		$ 8,453
Net loss per share, basic and diluted (in dollars per share)			$ 0.06		$ 0.45
Current assets:
Deferred commissions			$ 1,274
Prepaid expenses and other current assets			808
Total current assets			2,082
Deferred commissions, noncurrent			29,784
Total assets			31,866
Liabilities and stockholders’ equity
Deferred revenue			(2,817)
Total current liabilities			(2,817)
Deferred revenue, noncurrent			(1,071)
Total liabilities			(3,888)
Accumulated deficit			35,754
Total stockholders’ equity			35,754
Subscription
Revenue
Total revenue		370,855	236,422	[1]	$ 144,909	[1]
Subscription | As Reported
Revenue
Total revenue			239,177		143,136
Subscription | Adoption of ASU 2014-09 | Accounting Standards Update 2014-09
Revenue
Total revenue			(2,755)		1,773
Professional services and other
Revenue
Total revenue		$ 28,399	20,125	[1]	15,897	[1]
Professional services and other | As Reported
Revenue
Total revenue			20,813		17,190
Professional services and other | Adoption of ASU 2014-09 | Accounting Standards Update 2014-09
Revenue
Total revenue			$ (688)		$ (1,293)
[1]	See Note 2 for a summary of adjustments.
[2]	See Note 2 for a summary of adjustments. The cumulative effect adjustment to Accumulated Deficit and Total Stockholders' Equity (Deficit) related to the adoption of ASU No. 2014-09 (Topic 606) as of January 31, 2016 was $22.8 million.
[3]	See Note 2 for a summary of adjustments.
[4]	See Note 2 for a summary of adjustments.
[5]	See Note 2 for a summary of adjustments.

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($) $ in Thousands	Jul. 13, 2018	Feb. 17, 2017	Feb. 28, 2017	Jul. 31, 2018	Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017	[1]
Business Acquisition [Line Items]
Payments for business acquisition, net of cash acquired					$ 15,632	$ 0	[1]	$ 0
Goodwill					$ 18,089	$ 6,282	[2]
Stormpath Inc.
Business Acquisition [Line Items]
Total purchase price		$ 3,700
Shares included in total consideration (in shares)		200,000
Stormpath Inc. | Restricted common stock
Business Acquisition [Line Items]
Incremental shares issued (in shares)		800,000	800,000
Incremental shares issued		$ 8,600	$ 8,600
Stormpath Inc. | Stormpath Investors
Business Acquisition [Line Items]
Total purchase price		2,200
Stormpath Inc. | Stormpath Workforce
Business Acquisition [Line Items]
Total purchase price		1,500
Incremental shares issued		$ 9,100
ScaleFT, Inc.
Business Acquisition [Line Items]
Payments for business acquisition, net of cash acquired	$ 15,600
Cash received from acquisition	600
Purchased developed technology	4,600
Goodwill	$ 11,800
Acquisition related costs				$ 1,100
ScaleFT, Inc. | Purchased developed technology
Business Acquisition [Line Items]
Useful life of acquired intangible assets	3 years
[1]	See Note 2 for a summary of adjustments.
[2]	See Note 2 for a summary of adjustments.

Cash Equivalents and Short-te_3

Cash Equivalents and Short-term Investments - Schedule of Amortized Costs, Unrealized Gains and Losses and Estimated Fair Value of Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Cash Equivalents And Short Term Investments [Abstract]
Amortized Cost	$ 265,396	$ 101,967
Unrealized Gain	50	0
Unrealized Loss	(72)	(202)
Estimated Fair Value	265,374	101,765
Total Cash Equivalents And Short Term Investments [Abstract]
Amortized Cost	516,231	192,737
Unrealized Gain	50	0
Unrealized Loss	(73)	(202)
Estimated Fair Value	516,208	192,535
Commercial paper
Cash Equivalents And Short Term Investments [Abstract]
Amortized Cost		15,946
Unrealized Gain		0
Unrealized Loss		0
Estimated Fair Value		15,946
U.S. treasury securities
Cash Equivalents And Short Term Investments [Abstract]
Amortized Cost	195,913	61,896
Unrealized Gain	37	0
Unrealized Loss	(53)	(158)
Estimated Fair Value	195,897	61,738
Corporate debt securities
Cash Equivalents And Short Term Investments [Abstract]
Amortized Cost	69,483	24,125
Unrealized Gain	13	0
Unrealized Loss	(19)	(44)
Estimated Fair Value	69,477	24,081
Cash and Cash Equivalents
Cash Equivalents And Short Term Investments [Abstract]
Amortized Cost	250,835	90,770
Unrealized Gain	0	0
Unrealized Loss	(1)	0
Estimated Fair Value	250,834	90,770
Cash and Cash Equivalents | Money market funds
Cash Equivalents And Short Term Investments [Abstract]
Amortized Cost	247,426	90,770
Unrealized Gain	0	0
Unrealized Loss	0	0
Estimated Fair Value	247,426	$ 90,770
Cash and Cash Equivalents | Corporate debt securities
Cash Equivalents And Short Term Investments [Abstract]
Amortized Cost	3,409
Unrealized Gain	0
Unrealized Loss	(1)
Estimated Fair Value	$ 3,408

Cash Equivalents and Short-te_4

Cash Equivalents and Short-term Investments - Schedule of Contractual Maturities of Short-term Investments (Details) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Amortized Cost
Amortized cost, due within one year	$ 265,396	$ 93,421
Amortized cost, due between one to five years	0	8,546
Amortized Cost	265,396	101,967
Estimated Fair Value
Estimated fair value, due within one year	265,374	93,237
Estimated fair value, due between one to five years	0	8,528
Estimated fair value total	$ 265,374	$ 101,765

Cash Equivalents and Short-te_5

Cash Equivalents and Short-term Investments - Narrative (Details)	12 Months Ended
	Jan. 31, 2019USD ($)investment	Jan. 31, 2018USD ($)investment	Jan. 31, 2017USD ($)
Investments, Debt and Equity Securities [Abstract]
Number of short-term investments in unrealized loss positions | investment	34	23
Gross unrealized gains or losses from available-for-sale securities	$ 0	$ 0	$ 0
Realized gains or losses reclassified out of accumulated other comprehensive income	0	0	$ 0
Other-than-temporary impairment short term investment	$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Assets:
Cash equivalents, fair value	$ 250,834	$ 90,770
Short term investments, fair value	265,374	101,765
Total cash equivalents and short-term investments	516,208	192,535
Level 1
Assets:
Cash equivalents, fair value	247,426	90,770
Short term investments, fair value	0	0
Total cash equivalents and short-term investments	247,426	90,770
Level 2
Assets:
Cash equivalents, fair value	3,408	0
Short term investments, fair value	265,374	101,765
Total cash equivalents and short-term investments	268,782	101,765
Level 3
Assets:
Cash equivalents, fair value	0	0
Short term investments, fair value	0	0
Total cash equivalents and short-term investments	0	0
Commercial paper
Assets:
Short term investments, fair value		15,946
Commercial paper | Level 1
Assets:
Short term investments, fair value		0
Commercial paper | Level 2
Assets:
Short term investments, fair value		15,946
Commercial paper | Level 3
Assets:
Short term investments, fair value		0
U.S. treasury securities
Assets:
Short term investments, fair value	195,897	61,738
U.S. treasury securities | Level 1
Assets:
Short term investments, fair value	0	0
U.S. treasury securities | Level 2
Assets:
Short term investments, fair value	195,897	61,738
U.S. treasury securities | Level 3
Assets:
Short term investments, fair value	0	0
Corporate debt securities
Assets:
Short term investments, fair value	69,477	24,081
Corporate debt securities | Level 1
Assets:
Short term investments, fair value	0	0
Corporate debt securities | Level 2
Assets:
Short term investments, fair value	69,477	24,081
Corporate debt securities | Level 3
Assets:
Short term investments, fair value	0	0
Money market funds
Assets:
Cash equivalents, fair value	247,426	90,770
Money market funds | Level 1
Assets:
Cash equivalents, fair value	247,426	90,770
Money market funds | Level 2
Assets:
Cash equivalents, fair value	0	0
Money market funds | Level 3
Assets:
Cash equivalents, fair value	0	$ 0
Corporate debt securities
Assets:
Cash equivalents, fair value	3,408
Corporate debt securities | Level 1
Assets:
Cash equivalents, fair value	0
Corporate debt securities | Level 2
Assets:
Cash equivalents, fair value	3,408
Corporate debt securities | Level 3
Assets:
Cash equivalents, fair value	$ 0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Carrying Amounts and Estimated Fair Values of Convertible Note (Details) - Senior Notes - Convertible Senior Notes Due 2023 $ in Thousands	Jan. 31, 2019USD ($)
Net Carrying Amount Before Unamortized Debt Issuance Costs
Debt Instrument [Line Items]
Convertible senior notes value	$ 278,231
Estimated Fair Value
Debt Instrument [Line Items]
Convertible senior notes value	$ 620,565

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) $ / shares in Units, $ in Thousands	Jan. 31, 2019USD ($)$ / shares
Debt Instrument [Line Items]
Closing price of common stock (in dollars per share) | $ / shares	$ 82.43
Convertible Senior Notes Due 2023 | Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount | $	$ 345,000

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets, net - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Jan. 31, 2018		Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017
Goodwill [Line Items]
Goodwill	$ 6,282,000	[1]	$ 18,089,000	$ 6,282,000	[1]
Goodwill impairments			0	0		$ 0
Stock-based compensation included in capitalized software costs			500,000	1,200,000
Amortization expense			5,800,000	2,900,000		1,800,000
Research and development expense
Goodwill [Line Items]
Write-off of previously capitalized costs	$ 1,100,000
Capitalized internal-use software costs
Goodwill [Line Items]
Capitalized internal-use software			3,400,000	6,700,000
Amortization expense			$ 4,800,000	$ 2,700,000		$ 1,600,000
[1]	See Note 2 for a summary of adjustments.

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets, net - Schedule of Goodwill (Details) $ in Thousands	12 Months Ended
	Jan. 31, 2019USD ($)
Goodwill [Roll Forward]
Balance at January 31, 2018	$ 6,282	[1]
Goodwill recorded in connection with ScaleFT acquisition	11,807
Balance at January 31, 2019	$ 18,089
[1]	See Note 2 for a summary of adjustments.

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets, net - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017	[1]
Finite-Lived Intangible Assets [Line Items]
Gross	$ 25,461	$ 18,605
Accumulated Amortization	(11,565)	(5,730)
Write-offs	0	(1,114)	[1]	$ 0
Net	13,896	11,761
Capitalized internal-use software costs
Finite-Lived Intangible Assets [Line Items]
Gross	19,838	17,511
Accumulated Amortization	(9,969)	(5,172)
Write-offs	0	(1,077)
Net	9,869	11,262
Purchased developed technology
Finite-Lived Intangible Assets [Line Items]
Gross	4,600
Accumulated Amortization	(833)
Write-offs	0
Net	3,767
Software licenses
Finite-Lived Intangible Assets [Line Items]
Gross	1,023	1,094
Accumulated Amortization	(763)	(558)
Write-offs	0	(37)
Net	$ 260	$ 499
[1]	See Note 2 for a summary of adjustments.

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets, net - Remaining Amortization Expense (Details) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 6,302
2021	4,789
2022	1,459
2023	1,346
Total	$ 13,896	$ 11,761

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 62,563	$ 20,655
Less accumulated depreciation	(9,642)	(8,115)
Property and equipment, net	52,921	12,540	[1]
Depreciation expense	5,700	4,000		$ 2,400
Computers and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,668	5,384
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,012	7,083
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 47,883	$ 8,188
[1]	See Note 2 for a summary of adjustments.

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	$ 1,472	$ 1,306	$ 861
Additions	888	431	1,185
Write-offs	(262)	(265)	(740)
Balance, end of period	$ 2,098	$ 1,472	$ 1,306

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deposit related to early exercise of unvested options	$ 370	$ 1,119
Accrued expenses	6,392	3,389
Accrued taxes payable	1,195	835
Deferred rent, current	2,002	520
Other	0	324
Accrued expenses and other current liabilities	$ 9,959	$ 6,187	[1]
[1]	See Note 2 for a summary of adjustments.

Balance Sheet Components - Sc_4

Balance Sheet Components - Schedule of Other Liabilities, Noncurrent (Details) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deferred rent, noncurrent	$ 35,980	$ 5,010
Deferred tax liabilities	727	175
Other	2,292	1,832
Other liabilities, noncurrent	$ 38,999	$ 7,017	[1]
[1]	See Note 2 for a summary of adjustments.

Deferred Revenue and Performa_2

Deferred Revenue and Performance Obligations - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue recognized that was included in the contract liability balance	$ 157.9	$ 104.6
Unbilled receivables	$ 1.5	$ 0.8

Deferred Revenue and Performa_3

Deferred Revenue and Performance Obligations - Performance Obligations (Details) $ in Millions	Jan. 31, 2019USD ($)
Revenue from Contract with Customer [Abstract]
Revenue from remaining performance obligations	$ 728.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-02-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, percentage	53.00%
Performance obligations expected to be satisfied, expected timing	12 months

Debt and Financing Arrangemen_3

Debt and Financing Arrangements - Convertible Senior Notes (Details) - Senior Notes - Convertible Senior Notes Due 2023 $ / shares in Units, $ in Thousands	Feb. 23, 2018USD ($)day$ / shares	Jan. 31, 2019USD ($)day
Debt Instrument [Line Items]
Fixed interest rate	0.25%
Net proceeds from notes	$ 335,000
Initial conversion rate of common stock	0.0206795
Conversion price (in dollars per share) | $ / shares	$ 48.36
Limitation on sale of common stock, sale price threshold, number of trading days | day	20	20
Limitation on sale of common stock, sale price threshold, trading period | day	30	30
Threshold percentage of stock price trigger	130.00%	130.00%
Number of consecutive business days	5 days
Percentage of closing sale price in excess of convertible notes	98.00%
Redemption price percentage	100.00%
Effective interest rate	5.68%
Debt issuance costs	$ 10,000
Issuance costs attributable to liability component		$ 7,700
Additional Paid-in Capital
Debt Instrument [Line Items]
Issuance costs attributable to equity component		$ 2,320

Debt and Financing Arrangemen_4

Debt and Financing Arrangements - Schedule of Interest Expense (Details) - Senior Notes - Convertible Senior Notes Due 2023 $ in Thousands	12 Months Ended
	Jan. 31, 2019USD ($)
Debt Instrument [Line Items]
Contractual interest expense	$ 793
Amortization of debt issuance costs	1,085
Amortization of debt discount	13,194
Total	$ 15,072

Debt and Financing Arrangemen_5

Debt and Financing Arrangements - Schedule of Liability and Equity Component of 2023 Notes (Details) - Senior Notes - Convertible Senior Notes Due 2023 $ in Thousands	Jan. 31, 2019USD ($)
Liability component:
Principal	$ 345,000
Less: unamortized debt issuance costs and debt discount	(73,372)
Net carrying amount	271,628
Additional Paid-in Capital
Equity component:
2023 Notes	79,962
Less: issuance costs	(2,320)
Carrying amount of the equity component	$ 77,642

Debt and Financing Arrangemen_6

Debt and Financing Arrangements - Note Hedges and Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	Feb. 23, 2018	Jan. 31, 2019	Jan. 31, 2018	[1]	Jan. 31, 2017	[1]
Debt Instrument [Line Items]
Aggregate amount paid for cost of Note Hedge	$ 80,000
Number of warrants issued, subject to anti-dilution adjustments (in shares)	7.1
Per share value, shares issuable under warrants granted (in dollars per share)	$ 68.06
Proceeds from issuance of warrants related to convertible notes	$ 52,400	$ 52,440	$ 0		$ 0
Senior Notes | Convertible Senior Notes Due 2023
Debt Instrument [Line Items]
Shares issuable under warrants granted (in shares)	7.1
Conversion price (in dollars per share)	$ 48.36
[1]	See Note 2 for a summary of adjustments.

Debt and Financing Arrangemen_7

Debt and Financing Arrangements - Loan and Security Agreement (Details) - Loan and Security Agreement - Revolving Credit Facility - Line of Credit - USD ($)	Jan. 31, 2019	Nov. 21, 2016
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity		$ 40,000,000
Letters of credit issued and outstanding	$ 4,200,000

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details)	1 Months Ended	12 Months Ended
	Dec. 31, 2017USD ($)renewal_option	Jan. 31, 2019USD ($)	Jan. 31, 2018USD ($)		Jan. 31, 2017USD ($)
Other Commitments [Line Items]
Lease commitment amount		$ 244,678,000
Restricted cash		11,437,000	$ 8,284,000	[1]	$ 0	[1]
Deferred rent		38,000,000	5,500,000
Rent expense		23,300,000	10,600,000		$ 7,400,000
Financial Standby Letter of Credit
Other Commitments [Line Items]
Standby letter of credit		3,000,000
Letter of Credit
Other Commitments [Line Items]
Letters of credit issued and outstanding		12,700,000	$ 12,200,000
Draws on letters of credit		0
San Francisco - 10 Year Lease
Other Commitments [Line Items]
Lease term	10 years
Number of renewal options | renewal_option	2
Lease renewal term	5 years
Lease commitment amount	$ 206,300,000
Tenant improvement allowance (up to)	$ 24,700,000
Restricted cash		$ 8,000,000
[1]	See Note 2 for a summary of adjustments.

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Future Commitment Maturity Schedules (Details) $ in Thousands	Jan. 31, 2019USD ($)
Operating Leases
2020	$ 16,672
2021	26,606
2022	28,138
2023	27,777
2024	28,384
Thereafter	117,101
Total contractual obligations	244,678
Purchase Obligations
2020	19,668
2021	15,101
2022	15,101
2023	10,000
2024	0
Thereafter	0
Total contractual obligations	59,870
Total
2020	36,340
2021	41,707
2022	43,239
2023	37,777
2024	28,384
Thereafter	117,101
Total contractual obligations	$ 304,548

Common Stock and Stockholders_3

Common Stock and Stockholders' Equity - Narrative (Details) $ / shares in Units, $ in Thousands	Apr. 06, 2017shares	Jan. 31, 2019USD ($)vote$ / sharesshares	Jan. 31, 2018USD ($)$ / sharesshares		Jan. 31, 2017USD ($)shares
Class of Stock [Line Items]
Redeemable preferred stock outstanding (in shares)		0	0
Non-cash charitable contributions | $		$ 1,008	$ 708	[1]	$ 129	[1]
Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Redeemable convertible preferred stock converted to common class B stock (in shares)	59,491,640
Redeemable preferred stock outstanding (in shares)		0
Class A Common Stock
Class of Stock [Line Items]
Shares authorized (in shares)		1,000,000,000	1,000,000,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.0001	$ 0.0001
Common stock outstanding (in shares)		101,093,322	70,610,000
Number of votes per share | vote		1
Common stock, shares issued (in shares)		101,093,322	70,610,000
Class A Common Stock | Contribution of Nonmonetary Assets to Charitable Organization
Class of Stock [Line Items]
Issuance of common stock pursuant to charitable donation (in shares)		20,000	24,287
Non-cash charitable contributions | $		$ 1,000	$ 700
Class B Common Stock
Class of Stock [Line Items]
Common class B stock after conversion of redeemable convertible stock (in shares)	59,491,640
Shares authorized (in shares)		120,000,000	120,000,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.0001	$ 0.0001
Common stock outstanding (in shares)		11,059,181	33,361,000
Number of votes per share | vote		10
Common stock, shares issued (in shares)		11,059,181	33,361,000
Class B Common Stock | Contribution of Nonmonetary Assets to Charitable Organization
Class of Stock [Line Items]
Issuance of common stock pursuant to charitable donation (in shares)					13,935
Non-cash charitable contributions | $					$ 100
[1]	See Note 2 for a summary of adjustments.

Common Stock and Stockholders_4

Common Stock and Stockholders' Equity - Schedule of Common Stock Reserved for Future Issuance (Details)	Jan. 31, 2019shares
Class of Stock [Line Items]
Common stock reserved for future issuance and options and unvested RSUs outstanding (in shares)	38,130,287
Options and unvested RSUs outstanding
Class of Stock [Line Items]
Options and unvested RSUs outstanding (in shares)	22,639,330
Common stock, reserved for future issuance (in shares)	12,635,830
ESPP
Class of Stock [Line Items]
Common stock, reserved for future issuance (in shares)	2,855,127

Employee Incentive Plans - Sche

Employee Incentive Plans - Schedule of Stock-based Compensation Expense by Award Type (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 76,320	$ 49,860	$ 17,127
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	23,466	24,186	17,127
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	41,637	9,104	0
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	7,248	7,111	0
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,608	3,281	0
Restricted common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,361	$ 6,178	$ 0

Employee Incentive Plans - Sc_2

Employee Incentive Plans - Schedule of Stock-based Compensation Expense by Statement of Operations Location (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 76,320	$ 49,860	$ 17,127
Subscription
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	7,837	4,600	1,979
Professional services and other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	4,983	3,137	1,283
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	22,642	18,107	2,992
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	22,916	13,242	6,029
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 17,942	$ 10,774	$ 4,844

Employee Incentive Plans - Narr

Employee Incentive Plans - Narrative (Details) $ / shares in Units, $ in Thousands		Feb. 17, 2017USD ($)shares	Mar. 31, 2017offering_periodshares	Feb. 28, 2017USD ($)shares	Jan. 31, 2019USD ($)incentive_plan$ / sharesshares	Jan. 31, 2018USD ($)$ / sharesshares	Jan. 31, 2017USD ($)$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity incentive plans | incentive_plan					2
Options to purchase common stock outstanding (in shares) | shares					17,803,794	24,917,045
Weighted average grant date fair value of options granted (in usd per share) | $ / shares					$ 17.21	$ 5.40	$ 4
Grant date fair value of vested stock options					$ 23,800	$ 23,900	$ 13,100
Intrinsic value of options exercised					309,300	204,800	$ 6,900
Unrecognized stock-based compensation expense					$ 37,300
Number of options, granted (in shares) | shares					684,500
Issuance of common stock under employee stock purchase plan	[1]				$ 13,727	$ 8,369
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average stock-based compensation recognition period					3 years 1 month 6 days
Granted during period (in shares) | shares					3,392,285
Shares issued fair value					$ 184,300
Unrecognized compensation costs related to unvested restricted stock units					$ 187,200
Vested during period (in shares) | shares					976,248
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period (years)					10 years
Vesting period					4 years
Weighted average stock-based compensation recognition period					1 year 11 months 5 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, reserved for future issuance (in shares) | shares					2,855,127
Weighted average stock-based compensation recognition period					6 months
Unrecognized compensation costs related to unvested restricted stock units					$ 4,200
Shares authorized (in shares) | shares			3,000,000
ESPP offering period			12 months
Number of offering periods | offering_period			2
ESPP length of purchase period			6 months
Shares issued under ESPP (in shares) | shares					615,210	569,373
Weighted average price, shares issued under ESPP (in usd per share) | $ / shares					$ 22.31	$ 14.70
Options and unvested RSUs outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, reserved for future issuance (in shares) | shares					12,635,830
Stormpath Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-combination service consideration		$ 3,700
Stormpath Inc. | Restricted common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		2 years
Granted during period (in shares) | shares		800,000		800,000
Shares issued fair value		$ 8,600		$ 8,600
Stormpath Inc. | Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average stock-based compensation recognition period					1 month 6 days
Unrecognized compensation costs related to unvested restricted stock units					$ 100
Vested during period (in shares) | shares					400,000
Stormpath Inc. | Stormpath Workforce
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense				2,100	$ 1,100
Shares issued fair value		9,100
Pre-combination service consideration		$ 1,500
Stormpath Inc. | Stormpath Workforce | Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average stock-based compensation recognition period					6 months
Unrecognized compensation costs related to unvested restricted stock units				$ 5,500	$ 600
Vested during period (in shares) | shares					210,850
Stormpath Inc. | Stormpath Workforce | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years
Weighted average stock-based compensation recognition period					1 year 4 months 24 days
Shares issued fair value				$ 2,500
Number of options, granted (in shares) | shares				518,900
Minimum | Stormpath Inc. | Stormpath Workforce | Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				2 years
Expense recognition period					2 years
Maximum | Stormpath Inc. | Stormpath Workforce | Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				3 years
Expense recognition period					3 years
2009 Stock Plan | Stormpath Inc. | Stormpath Workforce | Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted during period (in shares) | shares				598,500
Shares issued fair value				$ 6,600
2017 Equity Incentive Plan | Class B Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase common stock outstanding (in shares) | shares					16,943,457
2017 Equity Incentive Plan | Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase common stock outstanding (in shares) | shares					860,337
Vesting Tranche One | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					1 year
Vesting percentage earned by employees after each completed year of service					25.00%
[1]	See Note 2 for a summary of adjustments. The cumulative effect adjustment to Accumulated Deficit and Total Stockholders' Equity (Deficit) related to the adoption of ASU No. 2014-09 (Topic 606) as of January 31, 2016 was $22.8 million.

Employee Incentive Plans - Sc_3

Employee Incentive Plans - Schedule of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
Number of Options
Number of options, outstanding beginning of period (in shares)	24,917,045
Number of options, granted (in shares)	684,500
Number of options, exercised (in shares)	(6,576,700)
Number of options, canceled (in shares)	(1,221,051)
Number of options, outstanding end of period (in shares)	17,803,794	24,917,045
Vested and expected to vest, number of options (in shares)	17,803,794
Vested and exercisable, number of options (in shares)	9,681,494
Weighted- Average Exercise Price
Options outstanding, weighted average exercise price beginning of period (in dollars per share)	$ 7.37
Options granted, weighted average exercise price (in dollars per share)	39.21
Options exercised, weighted average exercise price (in dollars per share)	5.61
Options canceled, weighted average exercise price (in dollars per share)	8.55
Options outstanding, weighted average exercise price end of period (in dollars per share)	9.16	$ 7.37
Vested and expected to vest, weighted average exercise price (in dollars per share)	9.16
Vested and exercisable, weighted average exercise price (in dollars per share)	$ 6.82
Additional Disclosures
Options outstanding, weighted average remaining contractual term	7 years 1 month 6 days	7 years 7 months 21 days
Options outstanding, aggregate intrinsic value	$ 1,304,446	$ 550,173
Vested and expected to vest, weighted average remaining contractual term	7 years 1 month 6 days
Vested and exercisable, weighted average remaining contractual term	6 years 7 months 6 days
Vested and expected to vest, aggregate intrinsic value	$ 1,304,446
Vested and exercisable, aggregate intrinsic value	$ 731,998

Employee Incentive Plans - Sc_4

Employee Incentive Plans - Schedule of Black-Scholes Option Pricing Model Estimated Fair Value Assumptions (Details)	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	40.00%
Expected volatility, minimum		40.00%	40.00%
Expected volatility, maximum		41.00%	44.00%
Expected term (in years)	6 years 3 months 18 days
Risk-free interest rate	2.70%
Risk-free interest rate, minimum		1.87%	1.13%
Risk-free interest rate, maximum		2.21%	2.28%
Expected dividend yield	0.00%	0.00%	0.00%
Stock options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		6 years 3 months 18 days	5 years 6 months
Stock options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		6 years 4 months 24 days	6 years 10 months 24 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum	39.00%	32.00%
Expected volatility, maximum	70.00%	38.00%
Risk-free interest rate, minimum	2.12%	0.95%
Risk-free interest rate, maximum	2.62%	1.73%
Expected dividend yield	0.00%	0.00%
ESPP | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 months	6 months
ESPP | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	1 year	1 year 2 months 12 days

Employee Incentive Plans - Sc_5

Employee Incentive Plans - Schedule of Restricted Stock Unit Activity (Details) - RSUs	12 Months Ended
	Jan. 31, 2019$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period (in shares) | shares	2,862,929
Granted during period (in shares) | shares	3,392,285
Vested during period (in shares) | shares	(976,248)
Forfeited during period (in shares) | shares	(443,430)
Outstanding at end of period (in shares) | shares	4,835,536
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 24.38
Granted during period (in dollars per share) | $ / shares	54.34
Vested during period (in dollars per share) | $ / shares	23.92
Forfeited during period (in dollars per share) | $ / shares	35.22
Outstanding at end of period (in dollars per share) | $ / shares	$ 44.49

Income Taxes - Schedule of Dome

Income Taxes - Schedule of Domestic and Foreign Components of Pre-tax Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017
Income Tax Disclosure [Abstract]
Domestic	$ (128,214)	$ (112,858)		$ (76,485)
Foreign	2,700	2,688		1,854
Loss before provision for (benefit from) income taxes	$ (125,514)	$ (110,170)	[1]	$ (74,631)	[1]
[1]	See Note 2 for a summary of adjustments.

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Provision for (Benefit from) Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017
Current:
Federal	$ 0	$ 0		$ 0
State	61	0		18
Foreign	667	183		426
Total current provision for income taxes	728	183		444
Deferred:
Federal	(620)	(32)		60
State	(130)	10		6
Foreign	5	(482)		(85)
Total deferred provision for (benefit from) income taxes	(745)	(504)		(19)
Total provision for (benefit from) income taxes	$ (17)	$ (321)	[1]	$ 425	[1]
[1]	See Note 2 for a summary of adjustments.

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax benefit related to stock based compensation		$ 1,300,000
Increase in valuation allowance	$ 86,600,000	18,600,000
Reduction in deferred tax asset before valuation allowance due to change in tax rate		56,500,000
Accrued penalties and interest related to unrecognized tax benefits	0	$ 0
Domestic Tax Authority
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating loss carryforwards	798,800,000
Domestic Tax Authority | Research Tax Credit Carryforward
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax credit carryforward	14,100,000
State and Local Jurisdiction
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating loss carryforwards	489,100,000
State and Local Jurisdiction | Research Tax Credit Carryforward
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax credit carryforward	9,800,000
State and Local Jurisdiction | California Enterprise Zone Credit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax credit carryforward	1,000,000
Foreign Tax Authority
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating loss carryforwards	$ 12,800,000

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Effective Income Tax Rate (Details)	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Income Tax Disclosure [Abstract]
Tax at federal statutory rate	21.00%	33.81%	34.00%
State income taxes, net of federal benefit	3.80%	3.40%	3.60%
Change in valuation allowance	(68.50%)	(27.10%)	(32.10%)
Stock-based compensation	45.50%	42.40%	(5.00%)
Tax Cuts and Jobs Act of 2017	0.00%	(51.30%)	0.00%
Other, net	(1.80%)	(0.90%)	(1.10%)
Effective tax rate	0.00%	0.30%	(0.60%)

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2019	Jan. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 202,471	$ 123,013
Stock-based compensation	13,185	7,926
Deferred revenue	1,312	213
Other reserves and accruals	13,113	3,084
Credits	791	791
Disallowed interest	1,769	0
Total deferred tax assets	232,641	135,027
Valuation allowance	(203,899)	(116,948)
Total deferred tax assets, net	28,742	18,079
Deferred tax liabilities:
Deferred commissions	(19,424)	(14,597)
Capitalized internal-use software costs	(2,047)	(2,389)
Goodwill	(217)	(175)
Depreciation and amortization	(6,492)	(441)
Total deferred tax liabilities	(28,180)	(17,602)
Net deferred tax asset	$ 562	$ 477

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross amount of unrecognized tax benefits as of the beginning of the year	$ 11,719	$ 5,775	$ 3,512
Additions based on tax positions related to a prior year	1,859	0	0
Additions based on tax positions related to current year	10,353	5,944	2,263
Gross amount of unrecognized tax benefits as of the end of the year	$ 23,931	$ 11,719	$ 5,775

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		12 Months Ended
		Jan. 31, 2019	Jan. 31, 2018		Jan. 31, 2017
Numerator:
Net loss	[1]	$ (125,497)	$ (109,849)	[2],[3],[4]	$ (75,056)	[2],[3],[4]
Denominator:
Weighted-average shares outstanding, basic and diluted (in shares)		107,504	83,004	[2]	19,038	[2]
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)		$ (1.17)	$ (1.32)		$ (3.94)	[2]
Class A Common Stock
Denominator:
Weighted-average shares outstanding, basic and diluted (in shares)		92,452	24,165		0
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)		$ (1.17)	$ (1.32)		$ 0
Class B Common Stock
Denominator:
Weighted-average shares outstanding, basic and diluted (in shares)		15,052	58,839		19,038
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)		$ (1.17)	$ (1.32)		$ (3.94)
Common Stock | Class A Common Stock
Numerator:
Net loss		$ (107,926)	$ (31,980)		$ 0
Common Stock | Class B Common Stock
Numerator:
Net loss		$ (17,571)	$ (77,869)		$ (75,056)
[1]	See Note 2 for a summary of adjustments. The cumulative effect adjustment to Accumulated Deficit and Total Stockholders' Equity (Deficit) related to the adoption of ASU No. 2014-09 (Topic 606) as of January 31, 2016 was $22.8 million.
[2]	See Note 2 for a summary of adjustments.
[3]	See Note 2 for a summary of adjustments.
[4]	See Note 2 for a summary of adjustments.

Net Loss Per Share - Schedule_2

Net Loss Per Share - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Per Share (Details) - shares shares in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	30,881	30,516	92,548
Unvested restricted common stock issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	400	800	0
Unvested RSUs issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	4,836	2,863	0
Unvested restricted stock awards issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	388	599	0
Shares committed under the ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	271	1,149	0
Unvested shares subject to repurchase
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	48	188	0
Conversion of convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	0	59,465
Shares related to convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	7,134	0	0
Issued and outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	17,804	24,917	32,866
Conversion of common stock warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	0	188
Conversion of convertible Series B warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	0	29

Net Loss Per Share - Narrative

Net Loss Per Share - Narrative (Details)	Feb. 23, 2018$ / shares
Convertible Senior Notes Due 2023 | Senior Notes
Debt Instrument [Line Items]
Conversion price (in dollars per share)	$ 48.36

Subsequent Events - (Details)

Subsequent Events - (Details) $ in Millions	Mar. 05, 2019USD ($)
Azuqua, Inc. | Subsequent Event
Subsequent Event [Line Items]
Total purchase price	$ 52.5

Uncategorized Items - okta-2019

Label	Element	Value
Restricted Cash and Cash Equivalents, Current	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue	$ 0	[1]
Restricted Cash and Cash Equivalents, Current	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue	0	[1]
Restricted Cash and Cash Equivalents, Current	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue	$ 1,384,000
[1]	See Note 2 for a summary of adjustments.