Pure Storage (PSTG) 10-Q 8 Dec 17 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Oct. 31, 2017	Nov. 30, 2017
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Oct. 31, 2017
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	PSTG
Entity Registrant Name	Pure Storage, Inc.
Entity Central Index Key	1,474,432
Current Fiscal Year End Date	--01-31
Entity Filer Category	Large Accelerated Filer
Class A
Entity Common Stock, Shares Outstanding (in shares)		112,788,614
Class B
Entity Common Stock, Shares Outstanding (in shares)		103,994,591

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Current assets:
Cash and cash equivalents	$ 182,039	$ 183,675
Marketable securities	369,337	362,986
Accounts receivable, net of allowance of $2,000 and $2,073 as of January 31, 2017 and October 31, 2017	202,006	168,978
Inventory	37,208	23,498
Deferred commissions, current	20,187	15,787
Prepaid expenses and other current assets	24,522	25,157
Total current assets	835,299	780,081
Property and equipment, net	84,264	81,695
Intangible assets, net	5,432	6,560
Deferred income taxes, non-current	965	844
Other assets, non-current	36,596	30,565
Total assets	962,556	899,745
Current liabilities:
Accounts payable	66,664	52,719
Accrued compensation and benefits	50,077	39,252
Accrued expenses and other liabilities	24,945	21,697
Deferred revenue, current	183,889	158,095
Liability related to early exercised stock options	568	1,362
Total current liabilities	326,143	273,125
Deferred revenue, non-current	173,641	145,031
Other liabilities, non-current	3,651	3,159
Total liabilities	503,435	421,315
Commitments and contingencies (Note 5)
Stockholders’ equity:
Preferred stock, par value of $0.0001 per share— 20,000 shares authorized as of January 31, 2017 and October 31, 2017; no shares issued and outstanding as of January 31, 2017 and October 31, 2017	0	0
Class A and Class B common stock, par value of $0.0001 per share— 2,250,000 (Class A 2,000,000, Class B 250,000) shares authorized as of January 31, 2017 and October 31, 2017; 204,364 (Class A 87,027, Class B 117,337) and 216,016 (Class A 109,178, Class B 106,838) shares issued and outstanding as of January 31, 2017 and October 31, 2017	20	20
Additional paid-in capital	1,428,024	1,281,452
Accumulated other comprehensive loss	(719)	(562)
Accumulated deficit	(968,204)	(802,480)
Total stockholders’ equity	459,121	478,430
Total liabilities and stockholders’ equity	$ 962,556	$ 899,745

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Accounts receivable, allowance	$ 2,073	$ 2,000
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	2,250,000,000	2,250,000,000
Common stock, shares issued (in shares)	216,016,000	204,364,000
Common stock, shares outstanding (in shares)	216,016,000	204,364,000
Class A
Common stock, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, shares issued (in shares)	109,177,866	87,027,000
Common stock, shares outstanding (in shares)	109,177,866	87,027,000
Class B
Common stock, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	106,837,859	117,337,000
Common stock, shares outstanding (in shares)	106,837,859	117,337,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Revenue:
Product	$ 223,196	$ 160,523	$ 536,634	$ 403,181
Support	54,478	36,433	148,132	96,936
Total revenue	277,674	196,956	684,766	500,117
Cost of revenue:
Product	75,392	54,725	179,289	131,618
Support	20,467	14,597	56,569	41,531
Total cost of revenue	95,859	69,322	235,858	173,149
Gross profit	181,815	127,634	448,908	326,968
Operating expenses:
Research and development	68,927	61,612	203,716	173,185
Sales and marketing	129,299	91,392	346,896	262,073
General and administrative	25,406	22,810	67,664	64,021
Legal settlement	0	30,000	0	30,000
Total operating expenses	223,632	205,814	618,276	529,279
Loss from operations	(41,817)	(78,180)	(169,368)	(202,311)
Other income (expense), net	1,138	(192)	6,399	1,127
Loss before provision for income taxes	(40,679)	(78,372)	(162,969)	(201,184)
Provision for income taxes	970	441	2,755	967
Net loss	$ (41,649)	$ (78,813)	$ (165,724)	$ (202,151)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.20)	$ (0.40)	$ (0.79)	$ (1.05)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	213,274	195,807	209,456	192,637

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (41,649)	$ (78,813)	$ (165,724)	$ (202,151)
Other comprehensive income (loss):
Change in unrealized net gain (loss) on available-for-sale securities	(439)	(554)	(157)	298
Comprehensive loss	$ (42,088)	$ (79,367)	$ (165,881)	$ (201,853)

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (165,724)	$ (202,151)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	45,525	35,978
Stock-based compensation expense	107,920	79,129
Other	879	1,051
Changes in operating assets and liabilities:
Accounts receivable, net	(33,630)	(38,186)
Inventory	(14,314)	(189)
Deferred commissions	(7,629)	1,844
Prepaid expenses and other current assets	(112)	39
Accounts payable	11,808	3,639
Accrued compensation and other liabilities	14,629	6,786
Deferred revenue	54,404	60,180
Net cash provided by (used in) operating activities	13,756	(51,880)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(44,351)	(64,602)
Purchase of intangible assets	0	(1,000)
Purchases of marketable securities	(151,998)	(483,558)
Sales of marketable securities	46,067	79,815
Maturities of marketable securities	99,021	38,213
Net increase in restricted cash	(2,029)	(5,600)
Net cash used in investing activities	(53,290)	(436,732)
CASH FLOWS FROM FINANCING ACTIVITIES
Net proceeds from exercise of stock options	15,761	10,725
Proceeds from issuance of common stock under employee stock purchase plan	22,137	25,606
Net cash provided by financing activities	37,898	36,331
Net decrease in cash and cash equivalents	(1,636)	(452,281)
Cash and cash equivalents, beginning of period	183,675	604,742
Cash and cash equivalents, end of period	182,039	152,461
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for income taxes	2,410	2,510
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION
Property and equipment purchased but not yet paid	9,831	5,956
Vesting of early exercised stock options	$ 794	$ 794

Business Overview

Business Overview	9 Months Ended
	Oct. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Overview	Business Overview Organization and Description of Business Pure Storage, Inc. (the Company, we, us, or other similar pronouns) was originally incorporated in the state of Delaware in October 2009 under the name OS76, Inc. In January 2010, we changed our name to Pure Storage, Inc. We are building a data platform that transforms business through a dramatic increase in performance and reduction in complexity and costs. We are headquartered in Mountain View, California and have wholly owned subsidiaries throughout the world.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Oct. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Principles of Consolidation The condensed consolidated financial statements include the accounts of the company and our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Unaudited Interim Consolidated Financial Information The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (U.S. GAAP) and applicable rules and regulations of the Securities and Exchange Commission (the SEC) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended January 31, 2017 . In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, comprehensive loss and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year 2018 or any future period. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the financial statements and accompanying notes. Actual results could differ from these estimates. Such estimates include, but are not limited to, the determination of best estimate of selling price included in multiple-element revenue arrangements, sales commissions, useful lives of intangible assets and property and equipment, fair values of stock-based awards, provision for income taxes, including related reserves, and contingent liabilities, among others. Management bases its estimates on historical experience and on various other assumptions which management believes to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Restricted Cash Restricted cash is comprised of cash collateral for a corporate credit card program and letters of credit related to our facility leases. As of January 31, 2017 and October 31, 2017 , we had restricted cash of $12.7 million and $14.8 million , which was included in other assets, non-current, in the condensed consolidated balance sheets. Marketable Securities We classify our marketable securities as available-for-sale at the time of purchase and reevaluate such classification at each balance sheet date. We may sell these securities at any time for use in current operations even if they have not yet reached maturity. As a result, we classify our securities, including those with maturities beyond twelve months, as current assets in the accompanying condensed consolidated balance sheets. We carry these securities at fair value and record unrealized gains and losses, in other comprehensive income (loss), which is reflected as a component of stockholders’ equity. We evaluate our securities to assess whether those with unrealized loss positions are other than temporarily impaired. We consider impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely we will sell the securities before the recovery of their cost basis. Realized gains and losses from the sale of marketable securities and declines in value deemed to be other than temporary are determined on the specific identification method. To date, there have been no declines in value deemed to be other than temporary in any of our securities. Realized gains and losses are reported in other income (expense), net in the condensed consolidated statements of operations. Deferred Commissions Deferred commissions consist of direct and incremental costs paid to our sales force related to customer contracts. The deferred commission amounts are recoverable through the revenue streams that will be recognized under the related customer contracts. Direct sales commissions are deferred when earned and amortized over the same period that revenue is recognized from the related customer contract. Amortization of deferred commissions is included in sales and marketing expense in the condensed consolidated statements of operations. As of January 31, 2017 and October 31, 2017 , we recorded deferred commissions, current, of $15.8 million and $20.2 million , and deferred commissions, non-current, of $14.9 million and $18.2 million , in other assets, non-current, in the condensed consolidated balance sheets. We recognized sales commission expenses of $21.6 million and $38.3 million during the three months ended October 31, 2016 and 2017 , and $58.8 million and $84.3 million during the nine months October 31, 2016 and 2017 . Recent Accounting Pronouncements Not Yet Adopted In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09), requiring an entity to recognize revenue when it transfers promised goods or services 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. ASU 2014-09 will supersede nearly all existing revenue recognition guidance under U.S. GAAP when it becomes effective. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers, deferring the effective date for ASU 2014-09 by one year. The new standard will be effective for us beginning on February 1, 2018. This standard may be adopted using either the full or modified retrospective methods. We anticipate adopting the standard retrospectively to all prior periods presented. While we are in the final stage of evaluating the impact of the new standard on our accounting policies, processes, and system requirements, and have assigned internal and external resources to assist in our evaluation and system implementation, we believe the impact on our consolidated financial statements upon the adoption of this standard will be primarily an increase in revenue, a decrease in deferred revenue balance, a decrease in sales and marketing expenses and an increase in deferred commissions balance. The impact to revenue and deferred revenue balance is primarily attributable to the removal of current limitation on contingent revenue accelerating revenue recognition for certain contracts. The impact to sales and marketing expenses and deferred commissions balance is primarily attributable to a change in current amortization period from contract term to expected customer life as required by the new standard. Additionally, we have made and will continue to make investments in systems to enable timely and accurate reporting under the new standard. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02). ASU 2016-02 requires lessees to recognize all leases with terms in excess of one year on their balance sheet as a right-of-use asset and a lease liability at the commencement date. The new standard also simplifies the accounting for sale and leaseback transactions. The amendments in this update will be effective for us beginning on February 1, 2019 and must be adopted using a modified retrospective method for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption is permitted. We are currently evaluating adoption methods and the impact of this standard on our consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 amends guidance on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities to require that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down. The measurement of credit losses for newly recognized financial assets and subsequent changes in the allowance for credit losses are recorded in the statements of operations. The amendments in this update will be effective for us beginning on February 1, 2020 with early adoption permitted on or after February 1, 2019. We are currently evaluating the impact of this standard on our consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18), which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 will be effective for us beginning on February 1, 2018 and will be applied on a retrospective basis. Early adoption is permitted. We do not expect the adoption of this standard to have any material impact on our consolidated financial statements. In May 2017, the FASB issued ASU No 2017-09, Compensation—Stock Compensation (Topic 718) — Scope of Modification Accounting, to clarify when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new standard, modification is required only if the fair value, the vesting conditions, or the classification of an award as equity or liability changes as a result of the change in terms or conditions. ASU 2017-09 will be effective for us beginning February 1, 2018 and will be applied prospectively. Early adoption is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.

Financial Instruments

Financial Instruments	9 Months Ended
	Oct. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Financial Instruments	Financial Instruments Fair Value Measurements We measure our cash equivalents, marketable securities, and restricted cash at fair value on a recurring basis. We define fair value as the exchange price that would be received from sale of an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. We measure our financial assets and liabilities at fair value at each reporting period using a fair value hierarchy which requires us to maximize the use of observable inputs and minimize 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 fair value: ▪ Level I —Observable inputs are unadjusted quoted prices in active markets for identical assets or liabilities; ▪ Level II —Observable inputs are quoted prices for similar assets and liabilities in active markets or inputs other than quoted prices that are observable for the assets or liabilities, either directly or indirectly through market corroboration, for substantially the full term of the financial instruments; and ▪ Level III —Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. These inputs are based on our own assumptions used to measure assets and liabilities at fair value and require significant management judgment or estimation. We classify our cash equivalents, marketable securities and restricted cash within Level 1 or Level 2 because they are valued using either quoted market prices or inputs other than quoted prices which are directly or indirectly observable in the market, including readily-available pricing sources for the identical underlying security which may not be actively traded. Our fixed income available-for-sale securities consist of high quality, investment grade securities from diverse issuers. The valuation techniques used to measure the fair value of our marketable securities were derived from non-binding market consensus prices that are corroborated by observable market data or quoted market prices for similar instruments. Cash Equivalents, Marketable Securities and Restricted Cash The following tables summarize our cash equivalents, marketable securities and restricted cash by significant investment categories as of January 31, 2017 and October 31, 2017 (in thousands): As of January 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash Equivalents Marketable Securities Restricted Cash Level 1 Money market accounts $ — $ — $ — $ 12,734 $ — $ — $ 12,734 Level 2 U.S. government treasury notes 148,298 22 (289 ) 148,031 13,226 134,805 — U.S. government agencies 40,398 2 (159 ) 40,241 — 40,241 — Corporate debt securities 185,701 242 (379 ) 185,564 — 185,564 — Foreign government bonds 2,377 2 (3 ) 2,376 — 2,376 — Total $ 376,774 $ 268 $ (830 ) $ 388,946 $ 13,226 $ 362,986 $ 12,734 As of October 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash Equivalents Marketable Securities Restricted Cash Level 1 Money market accounts $ — $ — $ — $ 14,763 $ — $ — $ 14,763 Level 2 U.S. government treasury notes 144,297 6 (419 ) 143,884 6,374 137,510 — U.S. government agencies 44,517 — (205 ) 44,312 — 44,312 — Corporate debt securities 187,616 209 (310 ) 187,515 — 187,515 — Total $ 376,430 $ 215 $ (934 ) $ 390,474 $ 6,374 $ 369,337 $ 14,763 The amortized cost and estimated fair value of our marketable securities are shown below by contractual maturity (in thousands): As of October 31, 2017 Amortized Cost Fair Value Due within one year $ 173,537 $ 173,413 Due in one to five years 196,519 195,924 Total $ 370,056 $ 369,337 Based on our evaluation of available evidence, we concluded that the gross unrealized losses on our marketable securities as of October 31, 2017 were temporary in nature. The following table presents gross unrealized losses and fair values for those investments that were in a continuous unrealized loss as of October 31, 2017 , aggregated by investment category (in thousands): Less than 12 months Greater than 12 months Total Fair Value Unrealized Loss Fair Unrealized Fair Unrealized U.S. government treasury notes $ 122,530 $ (381 ) $ 3,965 $ (38 ) $ 126,495 $ (419 ) U.S. government agencies 31,914 (106 ) 12,398 (99 ) 44,312 (205 ) Corporate debt securities 81,288 (168 ) 24,941 (142 ) 106,229 (310 ) Total $ 235,732 $ (655 ) $ 41,304 $ (279 ) $ 277,036 $ (934 ) Realized gains or losses on sale of marketable securities were not significant for all periods presented.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Oct. 31, 2017
Balance Sheet Components Disclosure [Abstract]
Balance Sheet Components	Balance Sheet Components Inventory Inventory consists of the following (in thousands): As of As of Raw materials $ 3,003 $ 5,926 Finished goods 20,495 31,282 Inventory $ 23,498 $ 37,208 Property and Equipment, Net Property and equipment, net, consists of the following (in thousands): As of As of Test equipment $ 105,955 $ 135,497 Computer equipment and software 54,521 66,270 Furniture and fixtures 4,494 5,337 Leasehold improvements 10,332 13,815 Total property and equipment 175,302 220,919 Less: accumulated depreciation and amortization (93,607 ) (136,655 ) Property and equipment, net $ 81,695 $ 84,264 Depreciation and amortization expense was $13.2 million and $15.2 million for the three months ended October 31, 2016 and 2017 , and $34.9 million and $44.4 million for the nine months ended October 31, 2016 and 2017 . Intangible Assets, Net Intangible assets, net, consist of the following (in thousands): As of As of Technology patents $ 10,125 $ 10,125 Accumulated amortization (3,565 ) (4,693 ) Intangible assets, net $ 6,560 $ 5,432 Intangible assets amortization expense was $376,000 for three months ended October 31, 2016 and 2017 , and $1.0 million and $1.1 million for the nine months ended October 31, 2016 and 2017 . The weighted-average remaining useful life of technology patents is 3.6 years. Due to the defensive nature of these patents, the amortization expense is included in general and administrative expenses in the condensed consolidated statements of operations. As of October 31, 2017 , expected amortization expense for intangible assets for each of the next five years is as follows (in thousands): Years Ending January 31, Estimated Future Amortization Expense Remainder of 2018 $ 376 2019 1,504 2020 1,504 2021 1,504 2022 544 Total $ 5,432 Accrued Expenses and Other Liabilities Accrued expenses and other liabilities consist of the following (in thousands): As of As of Sales and use tax payable $ 540 $ 1,256 Accrued professional fees 1,765 1,430 Accrued marketing 6,718 8,899 Accrued travel and entertainment expenses 2,235 4,112 Income tax payable 1,135 1,620 Other accrued liabilities 9,304 7,628 Total accrued expenses and other liabilities $ 21,697 $ 24,945

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Oct. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases During the nine months ended October 31, 2017 , we extended the lease term of an existing office facility with total additional lease obligations of approximately $2.0 million with the lease expiring through March 2019. Additionally, in August 2017, we entered into a seven -year term operating lease for approximately 45,831 square feet of office space in Mountain View, California with a total rent obligation and management fees of $32.2 million . Letters of Credit In connection with the lease executed in August 2017, we issued a letter of credit of $2.6 million . As of January 31, 2017 and October 31, 2017 , we had outstanding letters of credit in the aggregate amount of $7.7 million and $9.6 million , in connection with our facility leases. The letters of credit are collateralized by restricted cash in the same amount and mature at various dates through August 2026 . Legal Matters In September 2016, a purported securities class action entitled Ramsay v. Pure Storage, Inc., et al. was filed in the Superior Court of the State of California (San Mateo County) against us and certain of our officers, directors, investors and underwriters for our initial public offering (IPO), asserting claims under sections 11, 12 and 15 of the Securities Act. Substantially identical lawsuits were subsequently filed in the same Court, bringing the same claims against the same defendants. In October 2016, these actions were consolidated under the caption In re Pure Storage, Inc. Shareholder Litigation . In January 2017 and May 2017, the defendants filed demurrers (motions to dismiss) to plaintiffs' complaints on the grounds that the plaintiffs failed to state a claim under the Securities Act, and both times, in April 2017 and August 2017, the Court sustained the demurrers in defendants' favor as to all claims with leave to amend. The plaintiffs subsequently agreed to dismiss the lawsuit entirely, with no amendment or appeal, and in October 2017, the Court dismissed the consolidated action without prejudice. From time to time, we have become involved in claims and other legal matters arising in the normal course of business. We investigate these claims as they arise. Although claims are inherently unpredictable, we currently are not aware of any matters that may have a material adverse effect on our business, financial position, results of operations or cash flows. Accordingly, we have not recorded any loss contingency on our consolidated balance sheet as of October 31, 2017 . Indemnification Our arrangements generally include certain provisions for indemnifying customers against liabilities if our products or services infringe a third party’s intellectual property rights. Other guarantees or indemnification arrangements include guarantees of product and service performance and standby letters of credit for lease facilities. It is not possible to determine the maximum potential amount under these indemnification obligations due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each particular agreement. To date, we have not incurred any material costs as a result of such obligations and have not accrued any liabilities related to such obligations in the consolidated financial statements. In addition, we indemnify our officers, directors and certain key employees while they are serving in good faith in their respective capacities. To date, there have been no claims under any indemnification provisions.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Oct. 31, 2017
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Preferred Stock We have 20,000,000 authorized shares of undesignated preferred stock, the rights, preferences and privileges of which may be designated from time to time by our board of directors. As of October 31, 2017 , there were no shares of preferred stock issued or outstanding. Class A and Class B Common Stock We have two classes of authorized common stock, Class A common stock and Class B common stock. As of October 31, 2017 , we had 2,000,000,000 shares of Class A common stock authorized with a par value of $0.0001 per share and 250,000,000 shares of Class B common stock authorized with a par value of $0.0001 per share. As of October 31, 2017 , 109,177,866 shares of Class A common stock were issued and outstanding and 106,837,859 shares of Class B common stock were issued and outstanding.

Equity Incentive Plans

Equity Incentive Plans	9 Months Ended
	Oct. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Plans	Equity Incentive Plans Equity Incentive Plans We maintain two equity incentive plans: the 2009 Equity Incentive Plan (the 2009 Plan) and the 2015 Equity Incentive Plan (the 2015 Plan). In August 2015, our board of directors adopted, and in September 2015 our stockholders approved, the 2015 Plan, which became effective in connection with our initial public offering (IPO) and serves as the successor to the 2009 Plan. The 2015 Plan provides for grants of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards, and other forms of stock awards to our employees, directors and consultants. We ceased grants of new awards under the 2009 Plan after the effective date of the 2015 Plan, and no new grants will be made from the 2009 Plan. Outstanding awards granted under the 2009 Plan will remain subject to the terms of the 2009 Plan and applicable award agreements, until such outstanding awards that are stock options are exercised, terminated or expired by their terms. We initially reserved 27,000,000 shares of our Class A common stock for issuance under our 2015 Plan. The number of shares reserved for issuance under our 2015 Plan increases automatically on the first day of February of each year through 2025, in an amount equal to 5% of the total number of shares of our capital stock outstanding as of the immediately preceding January 31. The exercise price of stock options will generally not be less than 100% of the fair market value of our common stock on the date of grant, as determined by our board of directors. Our equity awards generally vest over a two to four year period and expire no later than ten years from the date of grant. 2015 Employee Stock Purchase Plan In August 2015, our board of directors adopted and our stockholders approved, the 2015 Employee Stock Purchase Plan (2015 ESPP), which became effective in connection with our IPO. A total of 3,500,000 shares of Class A common stock was initially reserved for issuance under the 2015 ESPP. The number of shares reserved for issuance under our 2015 ESPP increases automatically on the first day of February of each year through 2025, in an amount equal to the lesser of (i) 1% of the total number of shares of our capital stock outstanding as of the immediately preceding January 31, and (ii) 3,500,000 shares of Class A common stock. The 2015 ESPP allows eligible employees to purchase shares of our Class A common stock at a discount through payroll deductions (or other payroll contributions) of up to 30% of their eligible compensation, subject to a cap of 3,000 shares on any purchase date or $25,000 in any calendar year (as determined under applicable tax rules). The 2015 ESPP provides for 24 month offering periods beginning March 16th and September 16th of each year, and each offering period consists of four six -month purchase periods, subject to a reset provision. If the closing stock price on the offering date of a new offering falls below the closing stock price on the offering date of an ongoing offering, the ongoing offering would terminate immediately following the purchase of ESPP shares on the purchase date immediately preceding the new offering and participants in the terminated ongoing offering would automatically be enrolled in the new offering (ESPP reset). On each purchase date, eligible employees will purchase our Class A common stock at a price per share equal to 85% of the lesser of the fair market value of our Class A common stock (1) on the first trading day of the applicable offering period or (2) the purchase date. Our closing stock price on the new offering date of March 16, 2017 was lower than the closing stock prices for both the offerings that started on March 16, 2016 and September 16, 2016, which triggered an ESPP reset for those offerings. The ESPP reset resulted in a modification charge of approximately $9.0 million , which is being recognized over the new 24 -month offering period ending on March 15, 2019. In addition, the original remaining unamortized stock-based compensation expense for each of the offerings is being recognized over the same 24 -month offering period ending on March 15, 2019. We recognized stock-based compensation expense related to our 2015 ESPP of $4.8 million and $4.7 million during the three months ended October 31, 2016 and 2017 , and $13.4 million and $12.6 million during the nine months ended October 31, 2016 and 2017 . As of October 31, 2017 , there was $32.2 million of unrecognized stock-based compensation expense related to our 2015 ESPP which is expected to be recognized over a weighted-average period of approximately 1.4 years. Stock Options A summary of stock option activity under our equity incentive plans and related information is as follows: Options Outstanding Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (In Years) Aggregate Intrinsic Value (in thousands) Balance as of January 31, 2017 56,840,189 $ 7.15 7.0 $ 315,502 Options granted 1,000,000 14.92 Options exercised (5,502,179 ) 2.86 Options forfeited/cancelled (2,362,891 ) 14.41 Balance as of October 31, 2017 49,975,119 $ 7.43 6.4 $ 457,252 Vested and exercisable as of October 31, 2017 30,500,061 $ 4.84 5.9 $ 355,871 The aggregate intrinsic value of options vested and exercisable as of October 31, 2017 is calculated based on the difference between the exercise price and the closing price of $16.43 of our Class A common stock on October 31, 2017 . The weighted average fair value of the options granted during the nine months ended October 31, 2017 was $5.58 . As of October 31, 2017 , total unrecognized employee compensation cost related to outstanding options was $89.3 million , which is expected to be recognized over a weighted-average period of approximately 2.7 years. Restricted Stock Units A summary of the restricted stock unit activity under our 2015 Plan and related information is as follows: Number of Restricted Stock Units Outstanding Weighted- Average Grant Date Fair Value Aggregate Unvested Balance as of January 31, 2017 8,783,024 $ 13.06 $ 99,863 Granted 14,315,164 11.65 Vested (3,627,367 ) 12.33 Forfeited (1,292,330 ) 11.75 Unvested Balance as of October 31, 2017 18,178,491 $ 12.21 $ 298,674 As of October 31, 2017 , total unrecognized employee compensation cost related to unvested restricted stock units was $191.6 million , which is expected to be recognized over a weighted-average period of approximately 2.6 years. In March 2017, we granted 750,000 performance stock units (net of 77,000 canceled units during the nine months ended October 31, 2017 ) with both performance and service vesting conditions payable in common shares from 0% to 150% of the target number granted, contingent upon the degree to which the performance condition is met. In August 2017, we granted 464,744 performance stock units with both performance and service vesting conditions payable in common shares from 0% to 120% of the target number granted, contingent upon the degree to which the performance condition is met. For the performance stock units granted in March 2017, management determined it is probable that the performance condition will be satisfied and accordingly, we began recognizing stock-based compensation expense during the three months ended April 30, 2017. Stock-based compensation expense for these performance stock units was $1.3 million and $2.9 million for the three and nine months ended October 31, 2017 , recognized on an accelerated attribution method. The performance condition for the performance stock units granted in August 2017 will be determined at a future date and accordingly, there is no grant date for these awards from an accounting perspective and grant date fair value is not considered in the calculation of weighted-average grant date fair value in the table above. No stock-based compensation expense was recognized for these performance awards in the three and nine months ended October 31, 2017 . Stock-Based Compensation Expense The following table summarizes the components of stock-based compensation expense recognized in the condensed consolidated statements of operations (in thousands): Three Months Ended Nine Months Ended 2016 2017 2016 2017 Cost of revenue—product $ 138 $ 143 $ 425 $ 898 Cost of revenue—support 1,178 2,422 3,982 6,441 Research and development 15,241 18,073 40,875 51,632 Sales and marketing 8,468 12,104 24,719 34,169 General and administrative 3,210 6,121 9,128 14,780 Total stock-based compensation expense $ 28,235 $ 38,863 $ 79,129 $ 107,920 The tax benefit related to stock-based compensation expense for all periods presented was not material.

Net Loss per Share Attributable

Net Loss per Share Attributable to Common Stockholders	9 Months Ended
	Oct. 31, 2017
Earnings Per Share [Abstract]
Net Loss per Share Attributable to Common Stockholders	Net Loss per Share Attributable to Common Stockholders Basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities. Basic net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase. Diluted net loss per share attributable to common stockholders is computed by giving effect to all potentially dilutive common stock equivalents outstanding for the period. For purposes of this calculation, stock options, unvested restricted stock awards, repurchasable shares from early exercised stock options, and shares subject to ESPP withholding are considered to be common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is anti-dilutive. The rights, including the liquidation and dividend rights, of the holders of our Class A and Class B common stock are identical, except with respect to voting. As the liquidation and dividend rights are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. We did not present dilutive net loss per share on an if-converted basis because the impact was not dilutive. The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders (in thousands, except per share data): Three Months Ended Nine Months Ended 2016 2017 2016 2017 Net loss $ (78,813 ) $ (41,649 ) $ (202,151 ) $ (165,724 ) Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted 195,807 213,274 192,637 209,456 Net loss per share attributable to common stockholders, basic and diluted $ (0.40 ) $ (0.20 ) $ (1.05 ) $ (0.79 ) The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands): Three Months Ended Nine Months Ended 2016 2017 2016 2017 Stock options to purchase common stock 62,874 51,685 65,594 53,786 Restricted stock units 6,342 17,201 4,155 14,913 Early exercised stock options 2,246 196 2,451 287 Employee stock purchase plan 434 585 434 585 Total 71,896 69,667 72,634 69,571

Income Taxes

Income Taxes	9 Months Ended
	Oct. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our provision for income taxes was primarily due to taxes on international operations and state income taxes. The difference between the provision for income taxes that would be derived by applying the statutory rate to our loss before income taxes and the provision for income taxes recorded was primarily attributable to changes in our valuation allowance, non-deductible stock-based compensation expense and the tax rate differential between the U.S. and foreign countries. As of October 31, 2017 , there were no material changes to either the nature or the amounts of the uncertain tax positions previously determined for the year ended January 31, 2017 .

Segment Information

Segment Information	9 Months Ended
	Oct. 31, 2017
Segment Reporting [Abstract]
Segment Information	Segment Information Our chief operating decision maker is a group which is comprised of our Chief Executive Officer, our Chief Financial Officer, and our President. This group reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. We have one business activity and there are no segment managers who are held accountable for operations or operating results. Accordingly, we have a single reportable segment. The following table sets forth revenue by geographic area based on the billing address of our customers (in thousands): Three Months Ended Nine Months Ended 2016 2017 2016 2017 United States $ 152,134 $ 192,977 $ 385,464 $ 504,937 Rest of the world 44,822 84,697 114,653 179,829 Total revenue $ 196,956 $ 277,674 $ 500,117 $ 684,766 Long-lived assets by geographic area are summarized as follows (in thousands): As of As of United States $ 78,692 $ 80,387 Rest of the world 3,003 3,877 Total long-lived assets $ 81,695 $ 84,264

Basis of Presentation and Sum17

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Oct. 31, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of the company and our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Unaudited Interim Consolidated Financial Information	Unaudited Interim Consolidated Financial Information The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (U.S. GAAP) and applicable rules and regulations of the Securities and Exchange Commission (the SEC) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended January 31, 2017 . In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, comprehensive loss and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year 2018 or any future period.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the financial statements and accompanying notes. Actual results could differ from these estimates. Such estimates include, but are not limited to, the determination of best estimate of selling price included in multiple-element revenue arrangements, sales commissions, useful lives of intangible assets and property and equipment, fair values of stock-based awards, provision for income taxes, including related reserves, and contingent liabilities, among others. Management bases its estimates on historical experience and on various other assumptions which management believes to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities.
Restricted Cash	Restricted Cash Restricted cash is comprised of cash collateral for a corporate credit card program and letters of credit related to our facility leases.
Marketable Securities	Marketable Securities We classify our marketable securities as available-for-sale at the time of purchase and reevaluate such classification at each balance sheet date. We may sell these securities at any time for use in current operations even if they have not yet reached maturity. As a result, we classify our securities, including those with maturities beyond twelve months, as current assets in the accompanying condensed consolidated balance sheets. We carry these securities at fair value and record unrealized gains and losses, in other comprehensive income (loss), which is reflected as a component of stockholders’ equity. We evaluate our securities to assess whether those with unrealized loss positions are other than temporarily impaired. We consider impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely we will sell the securities before the recovery of their cost basis. Realized gains and losses from the sale of marketable securities and declines in value deemed to be other than temporary are determined on the specific identification method. To date, there have been no declines in value deemed to be other than temporary in any of our securities. Realized gains and losses are reported in other income (expense), net in the condensed consolidated statements of operations.
Deferred Commissions	Deferred Commissions Deferred commissions consist of direct and incremental costs paid to our sales force related to customer contracts. The deferred commission amounts are recoverable through the revenue streams that will be recognized under the related customer contracts. Direct sales commissions are deferred when earned and amortized over the same period that revenue is recognized from the related customer contract. Amortization of deferred commissions is included in sales and marketing expense in the condensed consolidated statements of operations.
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09), requiring an entity to recognize revenue when it transfers promised goods or services 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. ASU 2014-09 will supersede nearly all existing revenue recognition guidance under U.S. GAAP when it becomes effective. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers, deferring the effective date for ASU 2014-09 by one year. The new standard will be effective for us beginning on February 1, 2018. This standard may be adopted using either the full or modified retrospective methods. We anticipate adopting the standard retrospectively to all prior periods presented. While we are in the final stage of evaluating the impact of the new standard on our accounting policies, processes, and system requirements, and have assigned internal and external resources to assist in our evaluation and system implementation, we believe the impact on our consolidated financial statements upon the adoption of this standard will be primarily an increase in revenue, a decrease in deferred revenue balance, a decrease in sales and marketing expenses and an increase in deferred commissions balance. The impact to revenue and deferred revenue balance is primarily attributable to the removal of current limitation on contingent revenue accelerating revenue recognition for certain contracts. The impact to sales and marketing expenses and deferred commissions balance is primarily attributable to a change in current amortization period from contract term to expected customer life as required by the new standard. Additionally, we have made and will continue to make investments in systems to enable timely and accurate reporting under the new standard. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02). ASU 2016-02 requires lessees to recognize all leases with terms in excess of one year on their balance sheet as a right-of-use asset and a lease liability at the commencement date. The new standard also simplifies the accounting for sale and leaseback transactions. The amendments in this update will be effective for us beginning on February 1, 2019 and must be adopted using a modified retrospective method for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption is permitted. We are currently evaluating adoption methods and the impact of this standard on our consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 amends guidance on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities to require that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down. The measurement of credit losses for newly recognized financial assets and subsequent changes in the allowance for credit losses are recorded in the statements of operations. The amendments in this update will be effective for us beginning on February 1, 2020 with early adoption permitted on or after February 1, 2019. We are currently evaluating the impact of this standard on our consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18), which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 will be effective for us beginning on February 1, 2018 and will be applied on a retrospective basis. Early adoption is permitted. We do not expect the adoption of this standard to have any material impact on our consolidated financial statements. In May 2017, the FASB issued ASU No 2017-09, Compensation—Stock Compensation (Topic 718) — Scope of Modification Accounting, to clarify when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new standard, modification is required only if the fair value, the vesting conditions, or the classification of an award as equity or liability changes as a result of the change in terms or conditions. ASU 2017-09 will be effective for us beginning February 1, 2018 and will be applied prospectively. Early adoption is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.
Fair Value Measurements	Fair Value Measurements We measure our cash equivalents, marketable securities, and restricted cash at fair value on a recurring basis. We define fair value as the exchange price that would be received from sale of an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. We measure our financial assets and liabilities at fair value at each reporting period using a fair value hierarchy which requires us to maximize the use of observable inputs and minimize 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 fair value: ▪ Level I —Observable inputs are unadjusted quoted prices in active markets for identical assets or liabilities; ▪ Level II —Observable inputs are quoted prices for similar assets and liabilities in active markets or inputs other than quoted prices that are observable for the assets or liabilities, either directly or indirectly through market corroboration, for substantially the full term of the financial instruments; and ▪ Level III —Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. These inputs are based on our own assumptions used to measure assets and liabilities at fair value and require significant management judgment or estimation. We classify our cash equivalents, marketable securities and restricted cash within Level 1 or Level 2 because they are valued using either quoted market prices or inputs other than quoted prices which are directly or indirectly observable in the market, including readily-available pricing sources for the identical underlying security which may not be actively traded. Our fixed income available-for-sale securities consist of high quality, investment grade securities from diverse issuers. The valuation techniques used to measure the fair value of our marketable securities were derived from non-binding market consensus prices that are corroborated by observable market data or quoted market prices for similar instruments.

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
	Oct. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Summary of Cash Equivalents, Marketable Securities and Restricted Cash by Significant Investment Categories	The following tables summarize our cash equivalents, marketable securities and restricted cash by significant investment categories as of January 31, 2017 and October 31, 2017 (in thousands): As of January 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash Equivalents Marketable Securities Restricted Cash Level 1 Money market accounts $ — $ — $ — $ 12,734 $ — $ — $ 12,734 Level 2 U.S. government treasury notes 148,298 22 (289 ) 148,031 13,226 134,805 — U.S. government agencies 40,398 2 (159 ) 40,241 — 40,241 — Corporate debt securities 185,701 242 (379 ) 185,564 — 185,564 — Foreign government bonds 2,377 2 (3 ) 2,376 — 2,376 — Total $ 376,774 $ 268 $ (830 ) $ 388,946 $ 13,226 $ 362,986 $ 12,734 As of October 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash Equivalents Marketable Securities Restricted Cash Level 1 Money market accounts $ — $ — $ — $ 14,763 $ — $ — $ 14,763 Level 2 U.S. government treasury notes 144,297 6 (419 ) 143,884 6,374 137,510 — U.S. government agencies 44,517 — (205 ) 44,312 — 44,312 — Corporate debt securities 187,616 209 (310 ) 187,515 — 187,515 — Total $ 376,430 $ 215 $ (934 ) $ 390,474 $ 6,374 $ 369,337 $ 14,763
Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities by Contractual Maturity	The amortized cost and estimated fair value of our marketable securities are shown below by contractual maturity (in thousands): As of October 31, 2017 Amortized Cost Fair Value Due within one year $ 173,537 $ 173,413 Due in one to five years 196,519 195,924 Total $ 370,056 $ 369,337
Schedule of Gross Unrealized Losses and Fair Values for Investments that were in Continuous Unrealized Loss Position for Less Than 12 Months, Aggregated by Investments Category	The following table presents gross unrealized losses and fair values for those investments that were in a continuous unrealized loss as of October 31, 2017 , aggregated by investment category (in thousands): Less than 12 months Greater than 12 months Total Fair Value Unrealized Loss Fair Unrealized Fair Unrealized U.S. government treasury notes $ 122,530 $ (381 ) $ 3,965 $ (38 ) $ 126,495 $ (419 ) U.S. government agencies 31,914 (106 ) 12,398 (99 ) 44,312 (205 ) Corporate debt securities 81,288 (168 ) 24,941 (142 ) 106,229 (310 ) Total $ 235,732 $ (655 ) $ 41,304 $ (279 ) $ 277,036 $ (934 )

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Oct. 31, 2017
Balance Sheet Components Disclosure [Abstract]
Schedule of Inventory	Inventory consists of the following (in thousands): As of As of Raw materials $ 3,003 $ 5,926 Finished goods 20,495 31,282 Inventory $ 23,498 $ 37,208
Schedule of Property and Equipment, Net	Property and equipment, net, consists of the following (in thousands): As of As of Test equipment $ 105,955 $ 135,497 Computer equipment and software 54,521 66,270 Furniture and fixtures 4,494 5,337 Leasehold improvements 10,332 13,815 Total property and equipment 175,302 220,919 Less: accumulated depreciation and amortization (93,607 ) (136,655 ) Property and equipment, net $ 81,695 $ 84,264
Schedule of Intangible Assets, Net	Intangible assets, net, consist of the following (in thousands): As of As of Technology patents $ 10,125 $ 10,125 Accumulated amortization (3,565 ) (4,693 ) Intangible assets, net $ 6,560 $ 5,432
Schedule of Expected Amortization Expenses for Intangible Assets	As of October 31, 2017 , expected amortization expense for intangible assets for each of the next five years is as follows (in thousands): Years Ending January 31, Estimated Future Amortization Expense Remainder of 2018 $ 376 2019 1,504 2020 1,504 2021 1,504 2022 544 Total $ 5,432
Schedule of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following (in thousands): As of As of Sales and use tax payable $ 540 $ 1,256 Accrued professional fees 1,765 1,430 Accrued marketing 6,718 8,899 Accrued travel and entertainment expenses 2,235 4,112 Income tax payable 1,135 1,620 Other accrued liabilities 9,304 7,628 Total accrued expenses and other liabilities $ 21,697 $ 24,945

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	9 Months Ended
	Oct. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity Under Equity Incentive Plans and Related Information	A summary of stock option activity under our equity incentive plans and related information is as follows: Options Outstanding Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (In Years) Aggregate Intrinsic Value (in thousands) Balance as of January 31, 2017 56,840,189 $ 7.15 7.0 $ 315,502 Options granted 1,000,000 14.92 Options exercised (5,502,179 ) 2.86 Options forfeited/cancelled (2,362,891 ) 14.41 Balance as of October 31, 2017 49,975,119 $ 7.43 6.4 $ 457,252 Vested and exercisable as of October 31, 2017 30,500,061 $ 4.84 5.9 $ 355,871
Summary of Restricted Stock Unit Activity Under 2015 Plan	A summary of the restricted stock unit activity under our 2015 Plan and related information is as follows: Number of Restricted Stock Units Outstanding Weighted- Average Grant Date Fair Value Aggregate Unvested Balance as of January 31, 2017 8,783,024 $ 13.06 $ 99,863 Granted 14,315,164 11.65 Vested (3,627,367 ) 12.33 Forfeited (1,292,330 ) 11.75 Unvested Balance as of October 31, 2017 18,178,491 $ 12.21 $ 298,674
Summarizes the Components of Stock-Based Compensation	The following table summarizes the components of stock-based compensation expense recognized in the condensed consolidated statements of operations (in thousands): Three Months Ended Nine Months Ended 2016 2017 2016 2017 Cost of revenue—product $ 138 $ 143 $ 425 $ 898 Cost of revenue—support 1,178 2,422 3,982 6,441 Research and development 15,241 18,073 40,875 51,632 Sales and marketing 8,468 12,104 24,719 34,169 General and administrative 3,210 6,121 9,128 14,780 Total stock-based compensation expense $ 28,235 $ 38,863 $ 79,129 $ 107,920

Net Loss per Share Attributab21

Net Loss per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Oct. 31, 2017
Earnings Per Share [Abstract]
Summary of Computation of Basic and Diluted Net Loss per Share Attributable to Common Stockholders	The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders (in thousands, except per share data): Three Months Ended Nine Months Ended 2016 2017 2016 2017 Net loss $ (78,813 ) $ (41,649 ) $ (202,151 ) $ (165,724 ) Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted 195,807 213,274 192,637 209,456 Net loss per share attributable to common stockholders, basic and diluted $ (0.40 ) $ (0.20 ) $ (1.05 ) $ (0.79 )
Summary of Weighted-average Outstanding Shares Excluded from Computation of Diluted Net Loss per Share Attributable to Common Stockholders	The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands): Three Months Ended Nine Months Ended 2016 2017 2016 2017 Stock options to purchase common stock 62,874 51,685 65,594 53,786 Restricted stock units 6,342 17,201 4,155 14,913 Early exercised stock options 2,246 196 2,451 287 Employee stock purchase plan 434 585 434 585 Total 71,896 69,667 72,634 69,571

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Oct. 31, 2017
Segment Reporting [Abstract]
Schedule of Revenue by Geographic Area	The following table sets forth revenue by geographic area based on the billing address of our customers (in thousands): Three Months Ended Nine Months Ended 2016 2017 2016 2017 United States $ 152,134 $ 192,977 $ 385,464 $ 504,937 Rest of the world 44,822 84,697 114,653 179,829 Total revenue $ 196,956 $ 277,674 $ 500,117 $ 684,766
Schedule of Long-Lived Assets by Geographic Area	Long-lived assets by geographic area are summarized as follows (in thousands): As of As of United States $ 78,692 $ 80,387 Rest of the world 3,003 3,877 Total long-lived assets $ 81,695 $ 84,264

Basis of Presentation and Sum23

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016	Jan. 31, 2017
Accounting Policies [Abstract]
Restricted cash	$ 14,763		$ 14,763		$ 12,734
Deferred commissions, current	20,187		20,187		15,787
Deferred income taxes, non-current	18,200		18,200		$ 14,900
Sales commission expenses	$ 38,300	$ 21,600	$ 84,300	$ 58,800

Financial Instruments - Summary

Financial Instruments - Summary of Cash Equivalents, Marketable Securities and Restricted Cash by Significant Investment Categories (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 376,430	$ 376,774
Gross Unrealized Gains	215	268
Gross Unrealized Losses	(934)	(830)
Fair Value	390,474	388,946
Cash Equivalents	6,374	13,226
Marketable Securities	369,337	362,986
Restricted Cash	14,763	12,734
Money market accounts | Level 1
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	0	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	14,763	12,734
Cash Equivalents	0	0
Marketable Securities	0	0
Restricted Cash	14,763	12,734
U.S. government treasury notes | Level 2
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	144,297	148,298
Gross Unrealized Gains	6	22
Gross Unrealized Losses	(419)	(289)
Fair Value	143,884	148,031
Cash Equivalents	6,374	13,226
Marketable Securities	137,510	134,805
Restricted Cash	0	0
U.S. government agencies | Level 2
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	44,517	40,398
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(205)	(159)
Fair Value	44,312	40,241
Cash Equivalents	0	0
Marketable Securities	44,312	40,241
Restricted Cash	0	0
Corporate debt securities | Level 2
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	187,616	185,701
Gross Unrealized Gains	209	242
Gross Unrealized Losses	(310)	(379)
Fair Value	187,515	185,564
Cash Equivalents	0	0
Marketable Securities	187,515	185,564
Restricted Cash	$ 0	0
Foreign government bonds | Level 2
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		2,377
Gross Unrealized Gains		2
Gross Unrealized Losses		(3)
Fair Value		2,376
Cash Equivalents		0
Marketable Securities		2,376
Restricted Cash		$ 0

Financial Instruments - Schedul

Financial Instruments - Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities by Contractual Maturity (Details) $ in Thousands	Oct. 31, 2017USD ($)
Investments, Debt and Equity Securities [Abstract]
Due within one year, Amortized Cost	$ 173,537
Due in one to five years, Amortized Cost	196,519
Total, Amortized Cost	370,056
Due within one year, Fair Value	173,413
Due in one to five years, Fair Value	195,924
Total, Fair Value	$ 369,337

Financial Instruments - Sched26

Financial Instruments - Schedule of Gross Unrealized Losses and Fair Values for Investments that were in Continuous Unrealized Loss Position for Less Than 12 Months, Aggregated by Investments Category (Details) $ in Thousands	Oct. 31, 2017USD ($)
Fair Value
Less than 12 months	$ 235,732
Greater than 12 months	41,304
Total	277,036
Unrealized Loss
Less than 12 months	(655)
Greater than 12 months	(279)
Total	(934)
U.S. government treasury notes
Fair Value
Less than 12 months	122,530
Greater than 12 months	3,965
Total	126,495
Unrealized Loss
Less than 12 months	(381)
Greater than 12 months	(38)
Total	(419)
U.S. government agencies
Fair Value
Less than 12 months	31,914
Greater than 12 months	12,398
Total	44,312
Unrealized Loss
Less than 12 months	(106)
Greater than 12 months	(99)
Total	(205)
Corporate debt securities
Fair Value
Less than 12 months	81,288
Greater than 12 months	24,941
Total	106,229
Unrealized Loss
Less than 12 months	(168)
Greater than 12 months	(142)
Total	$ (310)

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Inventory (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Balance Sheet Components Disclosure [Abstract]
Raw materials	$ 5,926	$ 3,003
Finished goods	31,282	20,495
Inventory	$ 37,208	$ 23,498

Balance Sheet Components - Sc28

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Property Plant And Equipment [Line Items]
Total property and equipment	$ 220,919	$ 175,302
Less: accumulated depreciation and amortization	(136,655)	(93,607)
Property and equipment, net	84,264	81,695
Test equipment
Property Plant And Equipment [Line Items]
Total property and equipment	135,497	105,955
Computer equipment and software
Property Plant And Equipment [Line Items]
Total property and equipment	66,270	54,521
Furniture and fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	5,337	4,494
Leasehold improvements
Property Plant And Equipment [Line Items]
Total property and equipment	$ 13,815	$ 10,332

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Balance Sheet Components Disclosure [Abstract]
Depreciation and amortization	$ 15,200	$ 13,200	$ 44,400	$ 34,900
Intangible assets amortization expense	$ 376	$ 376	$ 1,100	$ 1,000
Finite-Lived Intangible Assets [Line Items]
Weighted-average remaining useful life			3 years 7 months 6 days

Balance Sheet Components - Sc30

Balance Sheet Components - Schedule of Intangible Assets, Net (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net	$ 5,432	$ 6,560
Technology patents
Finite-Lived Intangible Assets [Line Items]
Technology patents	10,125	10,125
Accumulated amortization	(4,693)	(3,565)
Intangible assets, net	$ 5,432	$ 6,560

Balance Sheet Components - Sc31

Balance Sheet Components - Schedule of Expected Amortization Expenses for Intangible Assets (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Balance Sheet Components Disclosure [Abstract]
Remainder of 2018	$ 376
2,019	1,504
2,020	1,504
2,021	1,504
2,022	544
Intangible assets, net	$ 5,432	$ 6,560

Balance Sheet Components - Sc32

Balance Sheet Components - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Balance Sheet Components Disclosure [Abstract]
Sales and use tax payable	$ 1,256	$ 540
Accrued professional fees	1,430	1,765
Accrued marketing	8,899	6,718
Accrued travel and entertainment expenses	4,112	2,235
Income tax payable	1,620	1,135
Other accrued liabilities	7,628	9,304
Total accrued expenses and other liabilities	$ 24,945	$ 21,697

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	1 Months Ended
	Aug. 31, 2017USD ($)ft²	Oct. 31, 2017USD ($)	Jan. 31, 2017USD ($)	Oct. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Total operating lease obligations		$ 2
Lease term	7 years
Area of leased office space (in sqft) | ft²	45,831
Base rent obligation	$ 32.2
Outstanding letters of credit	$ 2.6		$ 7.7	$ 9.6

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)	Oct. 31, 2017class$ / sharesshares	Jan. 31, 2017$ / sharesshares
Class Of Stock [Line Items]
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Number of classes of stock | class	2
Common stock, shares authorized (in shares)	2,250,000,000	2,250,000,000
Common stock, par value per share (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	216,016,000	204,364,000
Common stock, shares outstanding (in shares)	216,016,000	204,364,000
Class A
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, par value per share (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	109,177,866	87,027,000
Common stock, shares outstanding (in shares)	109,177,866	87,027,000
Class B
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, par value per share (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	106,837,859	117,337,000
Common stock, shares outstanding (in shares)	106,837,859	117,337,000

Equity Incentive Plans - Additi

Equity Incentive Plans - Additional Information (Details) $ in Thousands	Mar. 16, 2016USD ($)	Aug. 31, 2015periodshares	Oct. 31, 2017USD ($)shares	Oct. 31, 2016USD ($)	Oct. 31, 2017USD ($)planshares	Oct. 31, 2016USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of equity incentive plans | plan					2
Total stock-based compensation expense			$ 38,863	$ 28,235	$ 107,920	$ 79,129
Compensation cost, weighted average term					2 years 8 months 12 days
2015 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity awards of vest expire period (no later than)					10 years
2015 Equity Incentive Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price as percentage of fair market value of common stock					100.00%
Equity awards of vest period					2 years
2015 Equity Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity awards of vest period					4 years
2015 Equity Incentive Plan | Class A
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares initially reserved for issuance (in shares) | shares			27,000,000		27,000,000
Increase in shares reserved by percentage of capital stock					5.00%
2015 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee stock purchase plan offering period	24 months
Number of purchase periods | period		4
Purchase period, term		6 months
Modification charge related to the ESPP reset	$ 9,000
Total stock-based compensation expense			$ 4,700	$ 4,800	$ 12,600	$ 13,400
Unrecognized stock-based compensation expense			$ 32,200		$ 32,200
Compensation cost, weighted average term					1 year 4 months 24 days
2015 Employee Stock Purchase Plan | Class A
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in shares reserved by percentage of capital stock		1.00%
Purchase price as percentage of fair market value of common stock		85.00%
Shares reserved for future issuance (in shares) | shares		3,500,000
Payroll deductions percentage		30.00%
Share cap for ESPP at purchase date (in shares) | shares		3,000

Equity Incentive Plans - Stock

Equity Incentive Plans - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Oct. 31, 2017	Jan. 31, 2017
Options Outstanding, Number of Shares
Beginning balance (in shares)	56,840,189
Options granted (in shares)	1,000,000
Options exercised (in shares)	(5,502,179)
Options forfeited/cancelled (in shares)	(2,362,891)
Ending balance (in shares)	49,975,119	56,840,189
Options Outstanding, Number of Shares, Vested and exercisable (in shares)	30,500,061
Options Outstanding, Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 7.15
Options granted (in dollars per share)	14.92
Options exercised (in dollars per share)	2.86
Options forfeited/cancelled (in dollars per share)	14.41
Ending balance (in dollars per share)	7.43	$ 7.15
Weighted Average Exercise Price, Vested and exercisable (in dollars per share)	$ 4.84
Weighted- Average Remaining Contractual Life
Weighted Average Remaining Contractual Life	6 years 4 months 24 days	7 years
Weighted Average Remaining Contractual Life, Vested and exercisable	5 years 10 months 24 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value	$ 457,252	$ 315,502
Aggregate Intrinsic Value, Vested and exercisable	$ 355,871
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average fair value of the options granted (in dollars per share)	$ 5.58
Unrecognized compensation cost, stock options	$ 89,300
Compensation cost, weighted average term	2 years 8 months 12 days
Class A
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Closing price of stock (in dollars per share)	$ 16.43

Equity Incentive Plans - Restri

Equity Incentive Plans - Restricted Stock Units (Details) - USD ($)	1 Months Ended		3 Months Ended		9 Months Ended
	Aug. 31, 2017	Mar. 30, 2017	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016	Jan. 31, 2017
Weighted-Average Grant Date Fair Value
Compensation cost, weighted average term					2 years 8 months 12 days
Stock-based compensation expense			$ 38,863,000	$ 28,235,000	$ 107,920,000	$ 79,129,000
Restricted Stock Units
Number of Restricted Stock Units Outstanding
Unvested, Beginning balance (in shares)					8,783,024
Granted (in shares)					14,315,164
Vested (in shares)					(3,627,367)
Forfeited (in shares)					(1,292,330)
Unvested, Ending balance (in shares)			18,178,491		18,178,491
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share)					$ 13.06
Granted (in dollars per share)					11.65
Vested (in dollars per share)					12.33
Forfeited (in dollars per share)					11.75
Ending balance (in dollars per share)			$ 12.21		$ 12.21
Aggregate Intrinsic Value			$ 298,674,000		$ 298,674,000		$ 99,863,000
Compensation not yet recognized			191,600,000		$ 191,600,000
Compensation cost, weighted average term					2 years 7 months
Performance Shares | Granted March 2017
Number of Restricted Stock Units Outstanding
Granted (in shares)		750,000
Forfeited (in shares)					(77,000)
Weighted-Average Grant Date Fair Value
Stock-based compensation expense			1,300,000		$ 2,900,000
Performance Shares | Granted March 2017 | Minimum
Weighted-Average Grant Date Fair Value
Vesting rights, percentage of target number granted		0.00%
Performance Shares | Granted March 2017 | Maximum
Weighted-Average Grant Date Fair Value
Vesting rights, percentage of target number granted		150.00%
Performance Shares | Granted August 2017
Number of Restricted Stock Units Outstanding
Granted (in shares)	464,744
Weighted-Average Grant Date Fair Value
Stock-based compensation expense			$ 0		$ 0
Performance Shares | Granted August 2017 | Minimum
Weighted-Average Grant Date Fair Value
Vesting rights, percentage of target number granted	0.00%
Performance Shares | Granted August 2017 | Maximum
Weighted-Average Grant Date Fair Value
Vesting rights, percentage of target number granted	120.00%

Equity Incentive Plans - Stock-

Equity Incentive Plans - Stock-Based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 38,863	$ 28,235	$ 107,920	$ 79,129
Cost of revenue—product
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	143	138	898	425
Cost of revenue—support
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	2,422	1,178	6,441	3,982
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	18,073	15,241	51,632	40,875
Sales and marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	12,104	8,468	34,169	24,719
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 6,121	$ 3,210	$ 14,780	$ 9,128

Net Loss per Share Attributab39

Net Loss per Share Attributable to Common Stockholders - Summary of Computation of Basic and Diluted Net Loss per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Earnings Per Share [Abstract]
Net loss	$ (41,649)	$ (78,813)	$ (165,724)	$ (202,151)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	213,274	195,807	209,456	192,637
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.20)	$ (0.40)	$ (0.79)	$ (1.05)

Net Loss per Share Attributab40

Net Loss per Share Attributable to Common Stockholders - Summary of Weighted-average Outstanding Shares Excluded from Computation of Diluted Net Loss per Share Attributable to Common Stockholders (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares)	69,667	71,896	69,571	72,634
Stock options to purchase common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares)	51,685	62,874	53,786	65,594
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares)	17,201	6,342	14,913	4,155
Early exercised stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares)	196	2,246	287	2,451
Employee stock purchase plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares)	585	434	585	434

Segment Information - Additiona

Segment Information - Additional Information (Details)	9 Months Ended
	Oct. 31, 2017segment
Segment Reporting [Abstract]
Number of business activity	1
Number of reportable segments	1

Segment Information - Schedule

Segment Information - Schedule of Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 277,674	$ 196,956	$ 684,766	$ 500,117
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	192,977	152,134	504,937	385,464
Rest of the world
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 84,697	$ 44,822	$ 179,829	$ 114,653

Segment Information - Schedul43

Segment Information - Schedule of Long-Lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Total long-lived assets	$ 84,264	$ 81,695
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total long-lived assets	80,387	78,692
Rest of the world
Revenues From External Customers And Long Lived Assets [Line Items]
Total long-lived assets	$ 3,877	$ 3,003