Pure Storage (PSTG) 10-K 25 Mar 16 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Jan. 31, 2016	Mar. 22, 2016
Document And Entity Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jan. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
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	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float	$ 1,249
Class A Common Stock
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		47,780,342
Class B Common Stock
Document And Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		144,330,855

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Current assets:
Cash and cash equivalents	$ 604,742	$ 192,707
Accounts receivable, net of allowance of $210 and $944 as of January 31, 2015 and 2016	126,324	59,032
Inventory	20,649	21,605
Deferred commissions, current	15,703	9,431
Prepaid expenses and other current assets	20,652	11,195
Total current assets	788,070	293,970
Property and equipment, net	52,629	39,859
Intangible assets, net	6,980	8,284
Deferred income taxes, non-current	536	0
Other long-term assets	22,568	14,177
Total assets	870,783	356,290
Current liabilities:
Accounts payable	38,187	11,007
Accrued compensation and benefits	32,995	13,811
Accrued expenses and other liabilities	14,076	6,106
Deferred revenue, current	94,514	32,199
Liability related to early exercised stock options	4,760	6,485
Total current liabilities	184,532	69,608
Deferred revenue, non-current	121,690	41,470
Deferred income taxes, non-current	0	300
Other long-term liabilities	1,207	802
Total liabilities	307,429	112,180
Commitments and contingencies (Note 5)	0	0
Convertible preferred stock, par value of $0.0001 per share— 123,880 and no shares authorized as of January 31, 2015 and 2016, 122,281 and no shares issued and outstanding as of January 31, 2015 and 2016; aggregate liquidation preference of $551,858 as of January 31, 2015	0	543,940
Stockholders’ (deficit) equity:
Preferred stock, par value of $0.0001 per share— no and 20,000 shares authorized as of January 31, 2015 and 2016; no shares issued and outstanding as of January 31, 2015 and 2016	0	0
Class A and Class B common stock, par value of $0.0001 per share— 230,812 (Class A 1, Class B 230,811) and 2,250,000 (Class A 2,000,000, Class B 250,000) shares authorized as of January 31, 2015 and 2016; 36,465 (Class B 36,465) and 190,509 (Class A 28,769, Class B 161,740) shares issued and outstanding as of January 31, 2015 and 2016	19	4
Additional paid-in capital	1,118,670	41,749
Accumulated deficit	(555,335)	(341,583)
Total stockholders’ (deficit) equity	563,354	(299,830)
Total liabilities, convertible preferred stock, and stockholders’ (deficit) equity	$ 870,783	$ 356,290

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Accounts receivable, net of allowance	$ 944	$ 210
Convertible preferred stock, par value per share	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	0	123,879,952
Convertible preferred stock, shares issued	0	122,280,679
Convertible preferred stock, shares outstanding	0	122,280,679
Convertible preferred stock, aggregate liquidation preference	$ 0	$ 551,858
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	20,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, shares authorized	2,250,000,000	230,812,000
Common stock, shares issued	190,509,000	36,465,000
Common stock, shares outstanding	190,509,000	36,465,000
Class A Common Stock
Common stock, par value per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	2,000,000,000	1,000
Common stock, shares issued	28,769,572	0
Common stock, shares outstanding	28,769,572	0
Class B Common Stock
Common stock, par value per share	$ 0.0001	$ 0.0001
Common stock, shares authorized	250,000,000	230,811,000
Common stock, shares issued	161,739,883	36,465,000
Common stock, shares outstanding	161,739,883	36,465,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Revenue:
Product	$ 375,733	$ 154,836	$ 39,228
Support	64,600	19,615	3,505
Total revenue	440,333	174,451	42,733
Cost of revenue:
Product	132,870	63,425	19,974
Support	35,023	14,127	4,155
Total cost of revenue	167,893	77,552	24,129
Gross profit	272,440	96,899	18,604
Operating expenses:
Research and development	166,645	92,707	36,081
Sales and marketing	240,574	152,320	54,750
General and administrative	75,402	32,354	5,902
Total operating expenses	482,621	277,381	96,733
Loss from operations	(210,181)	(180,482)	(78,129)
Other income (expense), net	(2,002)	(1,412)	(141)
Loss before provision for income taxes	(212,183)	(181,894)	(78,270)
Provision for income taxes	1,569	1,337	291
Net loss	$ (213,752)	$ (183,231)	$ (78,561)
Net loss per share attributable to common stockholders, basic and diluted	$ (2.59)	$ (6.56)	$ (3.24)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	82,460	27,925	24,237

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' (Deficit) Equity - USD ($) $ in Thousands	Total	Series E Convertible Preferred Stock	Series F Convertible Preferred Stock	Series F-1 Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Stockholders' equity balance at Jan. 31, 2013	$ (39,150)				$ 3	$ 3,317	$ (42,470)
Stockholders' equity balance (in shares) at Jan. 31, 2013					27,438,000
Temporary equity balance at Jan. 31, 2013	$ 95,137
Temporary equity balance (in shares) at Jan. 31, 2013	79,409,000
Issuance of convertible preferred stock		$ 167,833
Issuance of convertible preferred stock (in shares)		24,697,000
Issuance of common stock upon exercise of stock options	$ 336				$ 0	336	0
Issuance of common stock upon exercise of stock options (in shares)					4,047,000
Repurchase of common stock in connection with tender offer (Note 9)	(7,202)				$ 0	0	(7,202)
Repurchase of common stock in connection with tender offer (Note 9) (in shares)					(3,046,000)
Stock-based compensation expense	8,298				$ 0	8,298	0
Vesting of early exercised stock options	192				0	192	0
Net loss	(78,561)				0	0	(78,561)
Stockholders' equity balance at Jan. 31, 2014	(116,087)				$ 3	12,143	(128,233)
Stockholders' equity balance (in shares) at Jan. 31, 2014					28,439,000
Temporary equity balance at Jan. 31, 2014	$ 262,970
Temporary equity balance (in shares) at Jan. 31, 2014	104,106,000
Issuance of convertible preferred stock		$ 450	$ 220,803	$ 59,717
Issuance of convertible preferred stock (in shares)		65,000	14,308,000	3,802,000
Issuance of common stock upon exercise of stock options, including stock options exercised via promissory notes (Note 9)	$ 3,047				$ 2	3,045	0
Issuance of common stock upon exercise of stock options, including stock options exercised via promissory notes (Note 9) (in shares)					11,879,000
Repurchase of common stock in connection with tender offer (Note 9)	(30,120)				$ (1)	0	(30,119)
Repurchase of common stock in connection with tender offer (Note 9) (in shares)					(3,803,000)
Repurchase of common stock from early exercised stock options	0				$ 0	0	0
Repurchase of common stock from early exercised stock options (in shares)					(50,000)
Stock-based compensation expense	25,399				$ 0	25,399	0
Vesting of early exercised stock options	1,162				0	1,162	0
Net loss	(183,231)				0	0	(183,231)
Stockholders' equity balance at Jan. 31, 2015	(299,830)				$ 4	41,749	(341,583)
Stockholders' equity balance (in shares) at Jan. 31, 2015					36,465,000
Temporary equity balance at Jan. 31, 2015	$ 543,940	$ 168,283	$ 220,803	$ 59,717
Temporary equity balance (in shares) at Jan. 31, 2015	122,280,679	24,761,984	14,307,603	3,801,746
Conversion of convertible preferred stock to common stock upon initial public offering	$ 543,940				$ 12	543,928	0
Conversion of convertible preferred stock to common stock upon initial public offering (in shares)					122,281,000
Temporary equity, conversion of convertible preferred stock to common stock upon initial public offering	$ (543,940)
Temporary equity, conversion of convertible preferred stock to common stock upon initial public offering (in shares)	(122,281,000)
Issuance of common stock upon initial public offering, net of offering costs of $4,539	$ 455,138				$ 3	455,135	0
Issuance of common stock upon initial public offering (in shares)					28,750,000
Issuance of common stock to Pure Good Foundation	$ 11,900					11,900
Issuance of common stock to Pure Good Foundation (in shares)					700,000
Issuance of common stock upon exercise of stock options (in shares)	2,313,598
Stock-based compensation expense	$ 58,225				$ 0	58,225	0
Vesting of early exercised stock options	1,725				0	1,725	0
Net loss	(213,752)				0	0	(213,752)
Stockholders' equity balance at Jan. 31, 2016	563,354				$ 19	1,118,670	(555,335)
Stockholders' equity balance (in shares) at Jan. 31, 2016					190,509,000
Temporary equity balance at Jan. 31, 2016	$ 0
Temporary equity balance (in shares) at Jan. 31, 2016	0
Issuance of common stock upon exercise of stock options, net of repurchases	$ 6,008				$ 0	$ 6,008	$ 0
Issuance of common stock upon, net of repurchases exercise of stock options (in shares)					2,313,000

Consolidated Statements of Con6

Consolidated Statements of Convertible Preferred Stock and Stockholders' (Deficit) Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Convertible Preferred Stock, value per share	$ 0.0001	$ 0.0001
Common Stock
Issuance costs	$ 4,539
Series E Convertible Preferred Stock
Convertible Preferred Stock, value per share		6.93	$ 6.93
Convertible preferred stock, issuance costs			$ 3,354
Series F Convertible Preferred Stock
Convertible Preferred Stock, value per share		$ 15.73
Convertible preferred stock, issuance costs		$ 4,197
Series F-1 Convertible Preferred Stock
Convertible Preferred Stock, value per share		$ 15.73
Convertible preferred stock, issuance costs		$ 69

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (213,752)	$ (183,231)	$ (78,561)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	32,254	15,392	4,431
Stock-based compensation expense	58,225	25,399	8,298
Contribution of common stock to the Pure Good Foundation	11,900	0	0
Other	(1,093)	277	92
Changes in operating assets and liabilities:
Accounts receivable, net	(67,292)	(44,197)	(12,038)
Inventory	1,481	(13,713)	(5,077)
Deferred commissions	(13,021)	(9,838)	(7,129)
Prepaid expenses and other assets	(8,704)	(6,550)	(4,400)
Accounts payable	24,901	3,474	5,243
Accrued compensation and other liabilities	24,710	12,450	6,771
Deferred revenue	142,535	56,842	15,141
Net cash used in operating activities	(7,856)	(143,695)	(67,229)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(39,355)	(42,227)	(12,273)
Purchases of intangible assets	0	(9,125)	0
Increase in restricted cash	(2,485)	(1,613)	(3,034)
Net cash used in investing activities	(41,840)	(52,965)	(15,307)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from initial public offering, net of issuance costs	459,425	0	0
Proceeds from issuance of convertible preferred stock, net of issuance costs	0	280,970	167,833
Net proceeds from exercise of stock options, including proceeds from repayment of promissory notes	6,008	7,665	2,670
Repurchase of common stock in connection with tender offers	0	(30,120)	(7,202)
Payments of deferred offering costs	(3,702)	(33)	0
Net cash provided by financing activities	461,731	258,482	163,301
Net increase in cash and cash equivalents	412,035	61,822	80,765
Cash and cash equivalents, beginning of period	192,707	130,885	50,120
Cash and cash equivalents, end of period	604,742	192,707	130,885
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for income taxes	1,118	429	87
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION
Conversion of convertible preferred stock to common stock upon initial public offering	543,940	0	0
Property and equipment purchased but not yet paid	6,212	1,323	1,224
Vesting of early exercised stock options and restricted stock awards	1,725	1,162	192
Cashless exercise of stock options during tender offers	0	2,057	640
Unpaid deferred offering costs	$ 546	$ 55	$ 0

Business Overview

Business Overview	12 Months Ended
	Jan. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business Overview	Note 1. 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 provide an enterprise data storage 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. Initial Public Offering In October 2015, we completed our IPO of Class A common stock, in which we sold 28,750,000 shares. The shares were sold at an initial public offering price of $17.00 per share for net proceeds of $459.4 million, after deducting underwriting discounts and commissions of $29.3 million but before deducting offering costs of $4.5 million. Upon the closing of our IPO, all outstanding shares of our convertible preferred stock automatically converted into 122,280,679 shares of Class B common stock. Following the IPO, we have two classes of authorized common stock – Class A common stock and Class B common stock.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Jan. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Note 2. Basis of Presentation and Summary of Significant Accounting Policies Principles of Consolidation The consolidated financial statements include the accounts of Pure Storage, Inc. and our wholly owned subsidiaries and have been prepared in conformity with accounting principles generally accepted in the United States (U.S. GAAP). All intercompany balances and transactions have been eliminated in consolidation. Stock Split In November 2013, we effected a 2-for-1 stock split. All references to common stock and convertible preferred stock shares and per share amounts including options to purchase common stock have been retroactively restated to reflect this stock split. Foreign Currency The functional currency of our foreign subsidiaries is the U.S. dollar. Transactions denominated in currencies other than the functional currency are remeasured to the functional currency at the average exchange rate in effect during the period. At the end of each reporting period, monetary assets and liabilities are remeasured using exchange rates in effect at the balance sheet date. Non-monetary assets and liabilities are remeasured at historical exchange rates. Foreign currency transaction gains and losses are recorded in other income (expense), net in the consolidated statements of operations. For the fiscal years ended January 31, 2014, 2015 and 2016, we recorded net foreign currency transaction losses of $16,000, $648,000, and $2.3 million, respectively. 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-deliverable 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. Concentration Risk Financial instruments that are exposed to concentration of credit risk consist primarily of cash and cash equivalents and accounts receivable. As of January 31, 2015 and 2016, substantially all of our cash and cash equivalents have been invested with one and three financial institutions, respectively, and such deposits exceed federally insured limits. Management believes that the financial institutions that hold our investments are financially sound and, accordingly, are subject to minimal credit risk. We define a customer as an end user that purchases our products and services from one of our channel partners or from us directly. Our revenue and accounts receivable are derived substantially from the United States across a multitude of industries. We perform ongoing evaluations to determine customer credit. As of January 31, 2015, we had one channel partner that individually represented 13% of total accounts receivable on that date. As of January 31, 2016, we had two channel partners that each individually represented 11% of total accounts receivable on that date. No single channel partner or customer represented over 10% of revenue for the fiscal years ended January 31, 2014, 2015 and 2016. We rely on a limited number of suppliers for our contract manufacturing and certain raw material components. In instances where suppliers fail to perform their obligations, we may be unable to find alternative suppliers or satisfactorily deliver our products to our customers on time. Cash and Cash Equivalents Cash and cash equivalents consist of cash in banks and highly liquid investments, primarily money market funds, purchased with an original maturity of three months or less. Restricted Cash Restricted cash is comprised of certificates of deposit related to our leases. As of January 31, 2015 and 2016, we had restricted cash of $4.6 million and $7.1 million, respectively, which was included in other long-term assets in the consolidated balance sheets. Fair Value of Financial Instruments The carrying value of our financial instruments, including cash equivalents, accounts receivable, accounts payable and accrued liabilities, approximates fair value. Accounts Receivable and Allowance Accounts receivable are recorded at the invoiced amount, and stated at realizable value, net of an allowance for doubtful accounts. Credit is extended to customers based on an evaluation of their financial condition and other factors. We generally do not require collateral or other security to support accounts receivable. We perform ongoing credit evaluations of our customers and maintain an allowance for doubtful accounts. We assess the collectability of the accounts by taking into consideration the aging of our trade receivables, historical experience, and management judgment. We write off trade receivables against the allowance when management determines a balance is uncollectible and no longer actively pursues collection of the receivable. The following table presents the changes in the allowance for doubtful accounts: Fiscal Year Ended January 31, 2014 2015 2016 (in thousands) Allowance for doubtful accounts, beginning balance $ 0 $ 160 $ 210 Provision 160 50 918 Writeoffs — — (184 ) Allowance for doubtful accounts, ending balance $ 160 $ 210 $ 944 Inventory Inventory consists of finished goods and component parts, which are purchased from contract manufacturers. Product demonstration units, which we regularly sell, are the primary component of our inventories. Inventories are stated at the lower of cost or market. Cost is determined using the specific identification method for finished goods and weighted-average method for component parts. We account for excess and obsolete inventory by reducing the carrying value to the estimated net realizable value of the inventory based upon management’s assumptions about future demand and market conditions. In addition, we record a liability for firm, non-cancelable and unconditional purchase commitments with contract manufacturers and suppliers for quantities in excess of future demand forecasts consistent with excess and obsolete inventory valuations. Inventory write-offs were insignificant for the fiscal years ended January 31, 2014, 2015 and 2016. Property and Equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization is computed using the straight-line method over the estimated useful lives of the respective assets (test equipment—2 years, computer equipment and software—2 to 3 years, furniture and fixtures—7 years). Leasehold improvements are amortized over the shorter of their estimated useful lives or the remaining lease term. Depreciation commences once the asset is placed in service. Intangible Assets Intangible assets are stated at cost, net of accumulated amortization. During the fiscal year ended January 31, 2015, we acquired certain technology patents for $9.1 million. This amount is being amortized on a straight-line basis over an estimated useful life of seven years. Impairment of Long-Lived Assets We review our long-lived assets, including property and equipment, and finite-lived intangible assets for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. We measure the recoverability of these assets by comparing the carrying amounts to the future undiscounted cash flows the assets are expected to generate. If the total of the future undiscounted cash flows is less than the carrying amount of an asset, we record an impairment charge for the amount by which the carrying amount of the asset exceeds its fair market value. There have been no impairment charges recorded in any of the periods presented in the consolidated financial statements. 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 consolidated statements of operations. As of January 31, 2015 and 2016, we recorded short-term deferred commissions of $9.4 million and $15.7 million, respectively, and long-term deferred commissions of $7.5 million and $14.3 million, respectively, in other long-term assets in the consolidated balance sheets. During the fiscal years ended January 31, 2014, 2015 and 2016, we recognized sales commission expenses of $11.0 million, $27.7 million, and $47.2 million, respectively. Deferred Offering Costs Deferred offering costs, consisting of legal, accounting and filing fees directly related to our IPO, are capitalized. The deferred offering costs were offset against the IPO proceeds upon the completion of the offering. Revenue Recognition We derive revenue from two sources: (1) product revenue which includes hardware and embedded software and (2) support revenue which includes customer support, hardware maintenance and software upgrades on a when-and-if-available basis. We recognize revenue when: · Persuasive evidence of an arrangement exists —We rely upon sales agreements and/or purchase orders to determine the existence of an arrangement. · Delivery has occurred —We typically recognize product revenue upon shipment, as title and risk of loss are transferred to our channel partners at that time. Products are typically shipped directly by us to customers, and our channel partners do not stock our inventory. · The fee is fixed or determinable —We assess whether the fee is fixed or determinable based on the payment terms associated with the transaction. · Collection is reasonably assured —We assess collectability based on credit analysis and payment history. Our product revenue is derived from the sale of hardware and operating system software that is integrated into the hardware and therefore deemed essential to its functionality. The hardware and the operating system software essential to the functionality of the hardware are considered non-software deliverables and, therefore, are not subject to industry-specific software revenue recognition guidance. Support revenue is derived from the sale of maintenance and support agreements. Maintenance and support agreements include the right to receive unspecified software upgrades and enhancements on a when-and-if-available basis, bug fixes, parts replacement services related to the hardware, as well as access to our cloud-based management and support platform. Revenue related to maintenance and support agreements are recognized ratably over the contractual term, which generally range from one to three years. Costs related to maintenance and support agreements are expensed as incurred. In addition, our Forever Flash Most of our arrangements, other than stand-alone renewals of maintenance and support agreements, are multiple-element arrangements with a combination of product and support related deliverables (as defined above). Under multiple-element arrangements, we allocate consideration at the inception of an arrangement to all deliverables based on the relative selling price method in accordance with the hierarchy provided by the multiple-element arrangement accounting guidance, which includes (i) vendor-specific objective evidence (“VSOE”), of selling price, if available; (ii) third-party evidence (“TPE”), of selling price, if VSOE is not available; and (iii) best estimate of selling price (“BESP”), if neither VSOE nor TPE is available. As discussed below, because we have not established VSOE for any of our deliverables and TPE typically cannot be obtained, we typically allocate consideration to all deliverables based on BESP. · VSOE —We determine VSOE based on our historical pricing and discounting practices for the specific products and services when sold separately. In determining VSOE, we require that a substantial majority of the stand-alone selling prices fall within a reasonably narrow pricing range. We have not established VSOE for any of our hardware and support related deliverables given that our pricing is not sufficiently concentrated (based on an analysis of separate sales of the deliverables) to conclude that we can demonstrate VSOE of selling prices. · TPE —When VSOE cannot be established for deliverables in multiple-element arrangements, we apply judgment with respect to whether we can establish a selling price based on TPE. TPE is determined based on competitor prices for interchangeable products or services when sold separately to similarly situated customers. However, because our products contain a significant element of proprietary technology and our solutions offer substantially different features and functionality, the comparable pricing of products with similar functionality typically cannot be obtained. · BESP —When neither VSOE nor TPE can be established, we utilize BESP to allocate consideration to deliverables in a multiple-element arrangement. Our process to determine BESP for products and support is based on qualitative and quantitative considerations of multiple factors, which primarily include historical sales, margin objectives and discount behavior. Additional considerations are given to other factors such as customer demographics, costs to manufacture products or provide support, pricing practices and market conditions. Deferred Revenue Deferred revenue consists of amounts that have been invoiced but that have not yet been recognized as revenue and primarily consists of support. The current portion of deferred revenue represents the amounts that are expected to be recognized as revenue within one year of the consolidated balance sheet date. Warranty Costs We generally provide a three-year warranty on hardware and a 90-day warranty on our software embedded in the hardware. Our hardware warranty provides for parts replacement for defective components and our software warranty provides for bug fixes. With respect to our hardware warranty obligation, we have a warranty agreement with our contract manufacturer under which our contract manufacturer is generally required to replace defective hardware within three years of shipment. Furthermore, our maintenance and support agreement provides for the same parts replacement that customers are entitled to under our warranty program, except that replacement parts are delivered according to targeted response times to minimize disruption to our customers’ critical business applications. Substantially all customers purchase maintenance and support agreements. Therefore, given the warranty agreement with our contract manufacturer and that substantially all our products sales are sold together with maintenance and support agreements, we generally do not have exposure related to warranty costs and no warranty reserve has been recorded. Research and Development Research and development costs are expensed as incurred. Research and development costs consist primarily of personnel costs including stock-based compensation expense, expensed prototype, to the extent there is no alternative use for that equipment, consulting services, depreciation of equipment used in research and development and allocated overhead costs. Software Development Costs We expense software development costs before technological feasibility is reached. We have determined that technological feasibility is reached shortly before the release of our products and as a result, the development costs incurred after the establishment of technological feasibility and before the release of those products have not been significant and accordingly, all software development costs have been expensed as incurred. Software development costs also include costs incurred related to our hosted applications used to deliver our support services. Capitalization begins when the preliminary project stage is complete, management with the relevant authority authorizes and commits to the funding of the software project, and it is probable the project will be completed and the software will be used to perform the intended function. Total costs related to our hosted applications incurred to date have been insignificant and as a result no software development costs were capitalized during the fiscal years ended January 31, 2014, 2015 and 2016. Advertising Expenses Advertising costs are expensed as incurred. Advertising expenses were $195,000, $1.4 million and $6.2 million for the fiscal years ended January 31, 2014, 2015 and 2016, respectively. Stock-Based Compensation We determine the fair value of our stock options under our equity plans and purchase rights issued to employees under our ESPP on the date of grant utilizing the Black-Scholes option pricing model, which is impacted by the fair value of our common stock, as well as changes in assumptions regarding a number of subjective variables. These variables include the expected common stock price volatility over the term of the awards, the expected term of the awards, risk-free interest rates and expected dividend yield. We recognize stock-based compensation expense for stock-based awards on a straight-line basis over the period during which an employee is required to provide services in exchange for the award (generally the vesting period of the award). Stock-based compensation expense is recognized only for those awards expected to vest. We estimate future forfeitures at the date of grant and revise the estimates, if necessary, in subsequent periods if actual forfeitures differ from those estimates. For stock-based awards granted to employees with a performance condition, we recognize stock-based compensation expense for these awards under the accelerated attribution method over the requisite service period when management determines it is probable that the performance condition will be satisfied. We determine the fair value of our stock options issued to non-employees on the date of grant utilizing the Black-Scholes option pricing model. Stock-based compensation expense for stock options issued to non-employees is recognized over the requisite service period or when it is probable that the performance condition will be satisfied. Options subject to vesting are periodically remeasured to current fair value over the vesting period. Comprehensive Loss We did not have any other comprehensive income or loss during the periods presented and therefore comprehensive loss was the same as net loss. Income Taxes We account for income taxes using the asset and liability method. Deferred income taxes are recognized by applying enacted statutory tax rates applicable to future years to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. The measurement of deferred tax assets is reduced, if necessary, by a valuation allowance to amounts that are more likely than not to be realized. We recognize tax benefits from uncertain tax positions only if we believe that it is more likely than not that the tax position will be sustained on examination by the taxing authorities based on the technical merits of the position. The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon settlement. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers Revenue from Contracts with Customers In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) Reclassifications As a result of the adoption of ASU 2015-17, we made the following reclassifications to the January 31, 2014 balance sheet: a $2.5 million decrease to non-current deferred tax assets, a $2.6 million decrease to current deferred tax liability, and an increase of $92,000 to non-current deferred tax liability, and to the January 31, 2015 balance sheet: a $5.5 million decrease to non-current deferred tax assets, a $5.8 million decrease to current deferred tax liability, and an increase of $300,000 to non-current deferred tax liability.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Jan. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 3. Fair Value Measurements 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 money market funds within Level I because they are valued using quoted market prices. We classify our restricted cash within Level II because they are valued using 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. The following tables set forth the fair value of our financial assets measured at fair value on a recurring basis as of January 31, 2015 and 2016 using the above input categories (in thousands): January 31, 2015 Level I Level II Level III Total Financial Assets: Cash and cash equivalents: Money market funds $ 190,621 $ — $ — $ 190,621 Restricted cash: Certificates of deposit — 4,648 — 4,648 Total assets measured at fair value $ 190,621 $ 4,648 $ — $ 195,269 January 31, 2016 Level I Level II Level III Total Financial Assets: Cash and cash equivalents: Money market funds $ 45,614 $ — $ — $ 45,614 Restricted cash: Certificates of deposit — 7,132 — 7,132 Total assets measured at fair value $ 45,614 $ 7,132 $ — $ 52,746

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Jan. 31, 2016
Balance Sheet Components Disclosure [Abstract]
Balance Sheet Components	Note 4. Balance Sheet Components Property and Equipment, Net Property and equipment, net consists of the following (in thousands): January 31, 2015 2016 Test equipment $ 37,059 $ 65,663 Computer equipment and software 19,022 31,388 Furniture and fixtures 2,460 2,852 Leasehold improvements 3,776 4,935 Total property and equipment 62,317 104,838 Less: accumulated depreciation and amortization (22,458 ) (52,209 ) Property and equipment, net $ 39,859 $ 52,629 Depreciation and amortization expense related to property and equipment was $4.4 million, $14.6 million and $31.0 million for the fiscal years ended January 31, 2014, 2015 and 2016, respectively. Intangible Assets, Net Intangible assets, net consist of the following (in thousands): January 31, 2015 2016 Technology patents $ 9,125 $ 9,125 Accumulated amortization (841 ) (2,145 ) Intangible assets, net $ 8,284 $ 6,980 Intangible assets amortization expense was $841,000 and $1.3 million for the fiscal years ended January 31, 2015 and 2016, respectively. No intangible assets amortization expense was recorded for the fiscal year ended January 31, 2014. Due to the defensive nature of these patents, the amortization is included in general and administrative expenses in the consolidated statements of operations. As of January 31, 2016, expected amortization expense for intangible assets for each of the next five years and thereafter is as follows (in thousands): Fiscal Year Ending January 31, Estimated Amortization Expense 2017 $ 1,304 2018 1,304 2019 1,304 2020 1,304 2021 1,304 Thereafter 460 Total $ 6,980 Accrued Expenses and Other Liabilities Accrued expenses and other liabilities consist of the following (in thousands): January 31, 2015 2016 Sales and use tax payable $ 591 $ 299 Accrued professional fees 1,502 3,044 Accrued travel and entertainment expenses 1,138 2,182 Income tax payable 779 1,791 Other accrued liabilities 2,096 6,760 Total accrued expenses and other liabilities $ 6,106 $ 14,076

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Jan. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 5. Commitments and Contingencies Operating Leases We lease our office facilities under operating lease agreements expiring through December 2025. Certain of these lease agreements have escalating rent payments. We recognize rent expense under such agreements on a straight-line basis over the lease term, and the difference between the rent paid and the straight-line rent is recorded in accrued expenses and other liabilities and other long-term liabilities in the accompanying consolidated balance sheets. As of January 31, 2016, the aggregate future minimum payments under non-cancelable operating leases consist of the following (in thousands): Fiscal Year Ending January 31, Operating Leases 2017 $ 14,402 2018 14,976 2019 10,637 2020 8,534 2021 5,477 Thereafter 6,728 Total $ 60,754 Rent expense recognized under our operating leases were $1.8 million, $7.5 million and $11.0 million for the fiscal years ended January 31, 2014, 2015 and 2016, respectively. Purchase Obligations As of January 31, 2015 and 2016, we had $626,000 and $5.9 million of non-cancelable contractual purchase obligations related to certain software service contracts. Letters of Credit As of January 31, 2015 and 2016, we had letters of credit in the aggregate amount of $4.6 million and $7.1 million, respectively, 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 March 2023. Legal Matters On November 4, 2013, EMC filed a complaint against us in the U.S. District Court for the District of Massachusetts, alleging that our hiring of EMC employees evidences a scheme to misappropriate EMC’s confidential information and trade secrets and to unlawfully interfere with EMC’s business relationships with its customers and contractual relationships with its employees. The complaint seeks damages and injunctive relief. On November 26, 2013, we answered and counterclaimed, denying EMC’s allegations and alleging that EMC surreptitiously obtained and tested our product in a manner that constituted misappropriation of our trade secrets, a breach of contract, breach of the covenant of good faith and fair dealing, unlawful interference with our contractual and business relationships as well as unfair competition and a violation of Massachusetts General Law 93A, Sections 2 and 11. On November 18, 2014, we amended our counterclaim, additionally alleging that EMC has engaged in commercial disparagement, violated the Lanham Act and engaged in defamation. Our counterclaim seeks damages and declaratory and injunctive relief. Fact discovery deadline has passed. Expert discovery is scheduled to conclude on April 15, 2016, and the deadline for filing dispositive motions is May 6, 2016. The District Court has scheduled a trial date for October 24, 2016.In a separate litigation matter, on November 26, 2013, EMC filed a complaint against us in the U.S. District Court for the District of Delaware, alleging infringement of five patents held by EMC. The five patents are U.S. Patent 6,904,556 entitled “Systems and Methods Which Utilize Parity Sets,” U.S. Patent 6,915,475 entitled “Data Integrity Management for Data Storage Systems,” U.S. Patent 7,373,464 entitled “Efficient Data Storage System” and the related U.S. Patent 7,434,015 entitled “Efficient Data Storage System” and U.S. Patent 8,375,187 entitled “I/O Scheduling For Flash Drives.” The complaint seeks damages and injunctive and equitable relief, with respect to the FlashArray 400-Series and predecessor products. Prior to trial, EMC dropped U.S. Patent No. 6,915,475 from the suit, and the District Court found, in a summary judgment ruling, that we did not infringe U.S. Patent No. 8,375,187 and did infringe certain claims of U.S. Patent No. 7,434,015, (“’015 patent”). The remaining two patents and the validity of ‘015 patent went to trial. On March 15, 2016, the jury returned a verdict finding that we did not infringe U.S. Patent Nos. 6,904,556 and 7,373,464, and that the ‘015 patent, which the District Court ruled us to have infringed, is valid. The jury awarded EMC in royalty damages for infringement of the '015 patent. The jury declined to award any lost profit damages. On March 21, 2016, EMC filed an additional complaint for infringement of the '015 patent with respect to the FlashArray//m product, which EMC did not seek permission from the District Court to add to the lawsuit when FlashArray//m was launched in June of 2015. This new complaint seeks damages and injunctive and equitable relief based on the District Court's previous ruling with respect to the '015 patent. The infringement ruling represents a reasonably possible loss contingency under the applicable accounting standards of up to $14.0 million. We believe there are strong grounds to challenge the infringement ruling by the District Court and the validity finding by the jury, with respect to the ‘015 patent. We intend to vigorously challenge the findings with respect to the ‘015 patent in post-trial motions before the District Court and, if necessary, appeal to the U.S. Court of Appeals for the Federal Circuit. At present, we do not believe it is probable that a loss has been incurred. As a result, we have not recorded any loss contingency on our consolidated balance sheet as of January 31, 2016. 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 sheets as of January 31, 2015 and 2016. 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.

Line of Credit

Line of Credit	12 Months Ended
	Jan. 31, 2016
Debt Disclosure [Abstract]
Line of Credit	Note 6. Line of Credit In August 2014, we entered into a two-year loan and security agreement with a financial institution to provide up to $15.0 million on a revolving line based on 80% of qualifying accounts receivable. Borrowings under this revolving line of credit bear interest at prime rate plus 1%. Interest expense is paid on a monthly basis based on the principal amount outstanding under the line of credit. The revolving line of credit matures in August 2016. Early termination is allowed but subject to a non-refundable termination fee of $150,000 if terminated on or after the first year from the effective date of the credit facility. Borrowings under this line of credit are collateralized by substantially all of our assets, excluding any intellectual property. We are also required to comply with certain financial covenants, including a minimum quarterly revenue target, delivery of financial and other information, as well as limitations on dispositions, mergers, or consolidations and other corporate activities. The terms of our outstanding loan and security agreements also restrict our ability to pay dividends. As of January 31, 2015 and 2016, we had no borrowings from this line of credit and we were in compliance with our financial covenants.

Convertible Preferred Stock

Convertible Preferred Stock	12 Months Ended
	Jan. 31, 2016
Temporary Equity [Abstract]
Convertible Preferred Stock	Note 7. Convertible Preferred Stock Upon the closing of our IPO in October 2015, all shares of our then-outstanding convertible preferred stock automatically converted on a one-to-one basis into an aggregate of 122,280,679 shares of Class B common stock. Convertible preferred stock outstanding as of January 31, 2015 and as of immediately prior to the conversion into Class B common stock consisted of the following (in thousands, except share data): Convertible Preferred Stock: Shares Authorized Shares Issued and Outstanding Aggregate Liquidation Preference Net Proceeds Series A 24,360,000 24,360,000 $ 5,075 $ 5,038 Series B 30,211,506 30,211,506 20,000 19,925 Series C 14,253,774 14,253,774 30,444 30,346 Series D 10,584,066 10,584,066 39,916 39,828 Series E 24,761,984 24,761,984 171,637 168,283 Series F 15,897,337 14,307,603 225,000 220,803 Series F-1 3,811,285 3,801,746 59,786 59,717 Total convertible preferred stock 123,879,952 122,280,679 $ 551,858 $ 543,940

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Jan. 31, 2016
Equity [Abstract]
Stockholders’ Equity	Note 8. Stockholders’ Equity Preferred Stock Upon the closing of our IPO in October 2015, we filed an Amended and Restated Certificate of Incorporation, which authorized 20,000,000 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 January 31, 2016, 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 January 31, 2016, 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 January 31, 2016, 28,769,572 shares of Class A common stock were issued and outstanding and 161,739,883 shares of Class B common stock were issued and outstanding. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting. Each share of Class A common stock is entitled to one vote per share. Each share of Class B common stock is entitled to 10 votes per share. Shares of Class B common stock may be converted to Class A common stock at any time at the option of the stockholder. Shares of Class B common stock automatically convert to Class A common stock upon the following: (i) sale or transfer of such share of Class B common stock; (ii) the death of the Class B common stockholder (or nine months after the date of death if the stockholder is one of our founders); and (iii) on the final conversion date, defined as the earlier of (a) the first trading day on or after the date on which the outstanding shares of Class B common stock represent less than 10% of the then outstanding Class A and Class B common stock; (b) the tenth anniversary of the IPO; or (c) the date specified by vote of the holders of a majority of the outstanding shares of Class B common stock, voting as a single class. Class A and Class B common stock are referred to as common stock throughout the notes to the consolidated financial statements, unless otherwise noted. In August 2015, we established the Pure Good Foundation as a non-profit organization, and in September 2015 we issued 700,000 shares of our Class B common stock to this foundation. As a result, we incurred a one-time general and administrative expense of $11.9 million during the fiscal year ended January 31, 2016, the amount of which was equal to the fair value of the shares of Class B common stock issued. We anticipate that the proposed programs of the Pure Good Foundation will include grants, humanitarian relief, volunteerism and social development projects. We believe that the Pure Good Foundation will foster employee morale, strengthen our community presence and provide increased brand visibility. Common Stock Reserved for Issuance As of January 31, 2016, we had reserved shares of common stock for future issuance as follows: January 31, 2016 Shares underlying outstanding stock options 68,879,087 Shares reserved for future equity awards 25,337,800 Shares reserved for future employee stock purchase plan awards 3,500,000 Total 97,716,887

Equity Incentive Plans

Equity Incentive Plans	12 Months Ended
	Jan. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Incentive Plans	Note 9. Equity Incentive Plans Equity Incentive Plans We maintain two equity incentive plans: the 2009 Equity Incentive Plan (our “2009 Plan”) and the 2015 Equity Incentive Plan (our “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 IPO in October 2015 and serves as the successor to our 2009 Plan. Our 2015 Plan provides for the issuance of incentive stock options to our employees and 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. No new awards are issued under our 2009 Plan after the effective date of our 2015 Plan. Outstanding awards granted under our 2009 Plan will remain subject to the terms of our 2009 Plan and applicable award agreements, until such outstanding awards that are stock options are exercised, terminated or expired by their terms, and until any restricted stock awards become vested or are forfeited. We have 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 will increase automatically on the first day of February of each of 2016 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. As of January 31, 2016, 25,337,800 shares of our Class A common stock were reserved for future issuance under the 2015 Plan. 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 in October 2015. A total of 3,500,000 shares of Class A common stock was initially reserved for issuance under the 2015 ESPP. 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). Except for the initial offering period, the 2015 ESPP provides for 24 month offering periods beginning March and September of each year, and each offering period will consist of four six-month purchase periods. The initial offering period began in October 2015, and will end on September 15, 2017. 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. For the first offering period, the fair market value of our Class A common stock on the offering date was $17.00, the price at which our Class A common stock was first sold to the public in our IPO. As of January 31, 2016, 3,500,000 shares were reserved for future issuance under the 2015 ESPP. Early Exercise of Stock Options and Promissory Notes Certain employees and directors have exercised options granted under the 2009 Plan prior to vesting. The unvested shares are subject to a repurchase right held by us at the original purchase price. The proceeds initially are recorded as liability related to early exercised stock options and reclassified to additional paid in capital as the repurchase right lapses. We issued 642,248 shares of common stock upon early exercise of stock options during the fiscal year ended January 31, 2015, for total exercise proceeds of $1.9 million. No unvested stock options were exercised during the fiscal year ended January 31, 2016. For the fiscal years ended January 31, 2015 and 2016, we repurchased 50,000 and 15,000 shares of unvested common stock related to early exercised stock options at the original purchase price due to the termination of an employee. As of January 31, 2015 and 2016, 4,710,454 and 2,809,264 shares held by employees and directors were subject to repurchase at an aggregate price of $6.5 million and $4.8 million. We entered into promissory notes with certain of our executives and employees in connection with the exercise of their stock option awards. These notes bore fixed interest rates ranging from 0.95% to 1.84% per annum. As of January 31, 2014, outstanding promissory notes were $3.2 million and 6,295,056 shares of common stock were outstanding from stock options exercised via promissory notes. As the promissory notes were solely collateralized by the underlying common stock, they are considered nonrecourse from an accounting standpoint and therefore, stock options exercised via nonrecourse promissory notes are not considered outstanding shares. Accordingly, as of January 31, 2014, we did not record these transactions related to promissory notes. During the fiscal year ended January 31, 2015, an additional 300,000 stock options were early exercised via a nonrecourse promissory note in the amount of $773,000, which was also not recorded in our financial statements. All outstanding promissory notes and the related accrued interest, which totaled $4.0 million, were repaid in full as of January 31, 2015, and accordingly, the underlying common stock was recorded as outstanding shares. Proceeds from the repayment of promissory notes were included in additional paid-in capital for the portion of the underlying common stock that was vested, and in liability related to early exercised stock options for the portion of the underlying common stock that was unvested. Stock Options A summary of 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 (Years) Aggregate Intrinsic Value (in thousands) Balance as of January 31, 2015 54,284,474 $ 3.02 8.3 $ 523,654 Options granted 19,269,524 15.76 Options exercised (2,313,598 ) 2.58 Options cancelled (2,361,313 ) 7.96 Balance as of January 31, 2016 68,879,087 $ 6.43 7.9 $ 505,131 Vested and exercisable as of January 31, 2016 24,297,716 $ 2.04 6.7 $ 267,213 Vested and expected to vest as of January 31, 2016 66,945,857 $ 6.37 7.9 $ 494,544 The aggregate intrinsic value of options vested and exercisable and vested and expected to vest as of January 31, 2016 is calculated based on the difference between the exercise price and the closing price $13.01 of our Class A common stock on January 31, 2016. The aggregate intrinsic value of options exercised for the fiscal years ended January 31, 2014, 2015 and 2016 was $8.5 million, $43.2 million and $29.5 million, respectively. The weighted-average grant date fair value of options granted was $1.50, $5.71 and $8.38 per share for the fiscal years ended January 31, 2014, 2015 and 2016, respectively. The total grant date fair value of options vested for the fiscal years ended January 31, 2014, 2015 and 2016 was $3.5 million, $9.9 million and $35.4 million, respectively. As of January 31, 2016, total unrecognized employee compensation cost, net of estimated forfeitures, was $201.8 million, which is expected to be recognized over a weighted-average period of approximately 3.7 years. To the extent the actual forfeiture rate is different from what we have estimated, stock-based compensation related to these awards will be different from our expectations. During the fiscal years ended January 31, 2014, 2015 and 2016, we granted options to purchase 3,883,654, 499,750, and 238,000 shares of common stock, net of cancellations, that vest upon satisfaction of a performance condition. For those options that management determined that it is probable that the performance condition will be satisfied, stock-based compensation expense of $596,000, $1.7 million and $2.5 million was recognized during the fiscal years ended January 31, 2014, 2015 and 2016, respectively. 2015 ESPP During the fiscal year ended January 31, 2016, we recognized $4.4 million of stock-based compensation expense related to our 2015 ESPP. As of January 31, 2016, there was $21.6 million of unrecognized stock-based compensation expense, net of estimated forfeitures, related to our 2015 ESPP that is expected to be recognized over the remaining term of the offering period. Determination of Fair Value The fair value of stock options granted to employees and to be purchased under ESPP is estimated on the grant date using the Black-Scholes option pricing model. This valuation model for stock-based compensation expense requires us to make assumptions and judgments about the variables used in the calculation including the fair value of the underlying common stock, expected term, the expected volatility of the common stock, a risk-free interest rate and expected dividend yield. We estimate the fair value of employee stock options and ESPP purchase rights using a Black-Scholes option pricing model with the following assumptions: Fiscal Year Ended January 31, 2014 2015 2016 Employee Stock Options Expected term (in years) 5.3 - 7.3 5.0 - 6.9 6.0 - 7.4 Expected volatility 65% - 69% 55% - 68% 48%-52% Risk-free interest rate 0.8% - 2.1% 1.3% - 2.2% 1.5%-1.9% Dividend rate — — — Fair value of common stock $1.46 - $2.98 $4.81 - $12.65 $13.94-$19.68 Employee Stock Purchase Plan Expected term (in years) — — 0.4 - 1.9 Expected volatility — — 49% Risk-free interest rate — — 0.1% - 0.7% Dividend rate — — — The assumptions used in the Black-Scholes option pricing model were determined as follows. Fair Value of Common Stock —Prior to our IPO in October 2015, our board of directors considered numerous objective and subjective factors to determine the fair value of our common stock at each grant date. These factors included, but were not limited to (i) contemporaneous third-party valuations of common stock; (ii) the prices for our convertible preferred stock sold to outside investors; (iii) the rights and preferences of convertible preferred stock relative to common stock; (iv) the lack of marketability of our common stock; (v) developments in the business; and (vi) the likelihood of achieving a liquidity event, such as an IPO or sale of Pure Storage, given prevailing market conditions. Subsequent to our IPO, we use the market closing price of our Class A common stock as reported on the New York Stock Exchange to determine the fair value of our common stock at each grant date. Expected Term —The expected term represents the period that our stock-based awards are expected to be outstanding. The expected term assumptions were determined based on the vesting terms, exercise terms and contractual lives of the options and ESPP purchase rights. Expected Volatility —Since we do not have a trading history of our common stock, the expected volatility was derived from the average historical stock volatilities of several public companies within the same industry that we consider to be comparable to our business over a period equivalent to the expected term of the stock option grants and ESPP purchase rights. Risk-Free Interest Rate —The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero-coupon U.S. Treasury notes with maturities approximately equal to the expected term of the stock option grants and ESPP purchase rights. Dividend Rate —We have never declared or paid any cash dividends and do not plan to pay cash dividends in the foreseeable future, and, therefore, use an expected dividend yield of zero. Non-Employee Stock Option Awards We estimate the fair value of non-employee stock options on the date of grant using a Black-Scholes option pricing model with the following assumptions: Fiscal Year Ended January 31, 2014 2015 2016 Expected term (in years) 10.0 10.0 10.0 Expected volatility 62% - 65% 62% - 63% 49% Risk-free interest rate 1.1% - 2.6% 1.6% - 2.6% 1.5% Dividend rate — — — Fair value of common stock $1.79 - $2.98 $9.40 - $12.40 $ 17.00 For the fiscal years ended January 31, 2014, 2015 and 2016, we granted non-employee stock options to purchase 1,126,400, 83,500, and 22,500 shares of common stock, respectively. We recognized stock-based compensation related to non-employee stock options of $1.1 million, $2.5 million and $3.1 million for the fiscal years ended January 31, 2014, 2015 and 2016, respectively. Restricted Stock Awards At the inception of the Company, we issued 18,300,000 shares of common stock to our founders under restricted stock agreements at a grant date fair value of $0.0005 per share that vested over four years. The unvested shares are subject to a repurchase right held by us at the original purchase price. For the fiscal year ended January 31, 2014, 2,812,500 shares of our restricted stock awards vested, and the related stock-based compensation was immaterial. All restricted stock awards were fully vested as of January 31, 2014. Repurchase of Common Stock in Connection with Tender Offers In November 2013, our board of directors approved a tender offer which allowed our employees to sell fully vested shares of common stock or unexercised stock options to the company. We repurchased 1,442,098 shares of common stock and 1,603,536 vested stock options from participating employees for a total consideration of $20.5 million, net of exercise proceeds of $640,000. The common stock repurchased was retired immediately thereafter. Of the $20.5 million total consideration, the fair value of the shares tendered net of exercise proceeds, was recorded in accumulated deficit, which totaled $7.2 million, while the amounts paid in excess of the fair value of our common stock at the time of repurchase were recorded as stock-based compensation expense, which totaled $13.3 million. In July 2014, our board of directors approved another tender offer which allowed our employees to sell fully vested shares of common stock or unexercised stock options to the company. We repurchased 735,426 shares of common stock and 3,067,910 vested stock options from participating employees for a total consideration of $57.7 million, net of exercise proceeds of $2.1 million. The common stock repurchased was retired immediately thereafter. Of the $57.7 million total consideration, the fair value of the shares tendered net of exercise proceeds, was recorded in accumulated deficit, which totaled $30.1 million, while the amounts paid in excess of the fair value of our common stock at the time of repurchase were recorded as stock-based compensation expense, which totaled $27.6 million. Stock-Based Compensation Expense The following table summarizes the components of stock-based compensation expense recognized in the consolidated statements of operations (in thousands): Fiscal Year Ended January 31, 2014 2015 2016 Cost of revenue—product $ 253 $ 303 $ 276 Cost of revenue—support 316 1,273 2,388 Research and development 11,477 22,512 31,135 Sales and marketing 9,014 22,466 16,966 General and administrative 506 6,479 7,460 Total stock-based compensation $ 21,566 $ 53,033 $ 58,225 The stock-based compensation expense for the fiscal years ended January 31, 2014 and 2015 included $13.3 million and $27.6 million related to the repurchase of common stock in excess of fair value in connection with tender offers.

Net Loss per Share Attributable

Net Loss per Share Attributable to Common Stockholders	12 Months Ended
	Jan. 31, 2016
Earnings Per Share [Abstract]
Net Loss per Share Attributable to Common Stockholders	Note 10. 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. We consider all series of our convertible preferred stock to be participating securities. Under the two-class method, the net loss attributable to common stockholders is not allocated to the convertible preferred stock as the holders of our convertible preferred stock do not have a contractual obligation to share in our losses. 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. The diluted net loss per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, convertible preferred stock, stock options, unvested restricted stock units, 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): Fiscal Year Ended January 31, 2014 2015 2016 Net loss $ (78,561 ) $ (183,231 ) (213,752 ) Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted 24,237 27,925 82,460 Net loss per share attributable to common stockholders, basic and diluted $ (3.24 ) $ (6.56 ) $ (2.59 ) 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): Fiscal Year Ended January 31, 2014 2015 2016 Convertible preferred stock (on an if-converted basis) 90,103 117,794 — Stock options to purchase common stock 33,715 50,429 61,795 Early exercised stock options and restricted stock awards 9,768 8,047 3,618 Employee stock purchase plan — — 170 Total 133,586 176,270 65,583

Income Taxes

Income Taxes	12 Months Ended
	Jan. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Note 11. Income Taxes The geographical breakdown of income (loss) before provision for income taxes is as follows (in thousands): Fiscal Year Ended January 31, 2014 2015 2016 Domestic $ (79,588 ) $ (186,922 ) $ (195,019 ) International 1,318 5,028 (17,164 ) Total $ (78,270 ) $ (181,894 ) $ (212,183 ) The components of the provision for income taxes are as follows (in thousands): Fiscal Year Ended January 31, 2014 2015 2016 Current: State 37 56 210 Foreign 162 1,073 2,198 Total 199 1,129 2,408 Deferred: Foreign 92 208 (839 ) Total provision for income taxes $ 291 $ 1,337 $ 1,569 The reconciliation of the federal statutory income tax rate and effective income tax rate is as follows: Fiscal Year Ended January 31, 2014 2015 2016 (in Tax at federal statutory rate $ (26,611 ) $ (61,844 ) $ (72,142 ) State tax, net of federal benefit 32 44 152 Stock-based compensation expense 1,570 5,328 10,866 Research and development tax credits (1,036 ) (1,999 ) (3,832 ) Foreign rate differential (194 ) (429 ) 7,106 Change in valuation allowance 26,152 60,042 58,979 Other 378 195 440 Provision for income taxes $ 291 $ 1,337 $ 1,569 Deferred income taxes reflect the net effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The significant component of our deferred tax assets and liabilities were as follows: January 31, 2015 2016 (in thousands) Deferred tax assets: Net operating loss carryforwards $ 101,815 $ 137,456 Tax credit carryover 6,136 12,406 Accruals and reserves 729 1,921 Deferred revenue 3,538 20,314 Stock-based compensation expense 4,258 12,588 Depreciation and amortization 2,054 3,397 Charitable contribution carryforwards — 4,380 Total deferred tax assets 118,530 192,462 Deferred tax liabilities: Deferred commissions (5,924 ) (11,000 ) Total deferred tax liabilities (5,924 ) (11,000 ) Valuation allowance (112,906 ) (180,926 ) Net deferred tax assets (liabilities), net of valuation allowance $ (300 ) $ 536 As of January 31, 2016, the undistributed earnings of $7.3 million from non-U.S. operations held by our foreign subsidiaries are designated as permanently reinvested outside the U.S. Accordingly, no additional U.S. income taxes or additional foreign withholding taxes have been provided thereon. Determination of the amount of unrecognized deferred tax liability related to these earnings is not practicable. As of January 31, 2016, we had net operating loss carryforwards for federal income tax purposes of approximately $392.4 million and state income tax purposes of approximately $402.2 million. These net operating loss carryforwards will expire, if not utilized, beginning in 2028 for federal and state income tax purposes. As of January 31, 2016, approximately $27.7 million of federal net operating loss carryforwards and $30.2 million of state net operating loss carryforwards are related to excess tax benefits from stock-based compensation expense. The tax benefits associated with net operating losses attributed to stock-based compensation expense will be credited to additional paid-in capital when realized. We had federal and state research and development tax credit carryforwards of approximately $10.0 million and $9.9 million as of January 31, 2016. The federal research and development tax credit carryforwards will expire commencing in 2028, while the state research and development tax credit carryforwards have no expiration date. Realization of deferred tax assets is dependent on future taxable income, the existence and timing of which is uncertain. Based on our history of losses, management has determined that it is more likely than not that the U.S. deferred tax assets will not be realized, and accordingly has placed a full valuation allowance on the net U.S. deferred tax assets. The valuation allowance increased by $28.8 million, $66.6 million, and $68.0million, respectively, during the fiscal years ended January 31, 2014, 2015 and 2016. Utilization of the net operating loss carryforwards and credits may be subject to substantial annual limitation due to the ownership change limitations provided by Section 382 of the Internal Revenue Code of 1986, as amended, and similar state provisions. The annual limitation may result in the expiration of net operating losses and credits before utilization. Uncertain Tax Positions The activity related to the unrecognized tax benefits is as follows: Fiscal Year Ended January 31, 2014 2015 2016 (in thousands) Gross unrecognized tax benefits—beginning balance $ 479 $ 4,676 $ 13,874 Decreases related to tax positions taken during prior years (10 ) — (3,969 ) Increases related to tax positions taken during prior years — — 35 Increases related to tax positions taken during current year 4,207 9,198 5,530 Gross unrecognized tax benefits—ending balance $ 4,676 $ 13,874 $ 15,470 As of January 31, 2016, our gross unrecognized tax benefit was approximately $15.5 million and if recognized, would have no impact to the effective tax rate because it would be offset by the reversal of deferred tax assets which are subject to a full valuation allowance. As of January 31, 2016, we had no current or cumulative interest and penalties related to uncertain tax positions. It is difficult to predict the final timing and resolution of any particular uncertain tax position. Based on our assessment, including experience and complex judgments about future events, we do not expect that changes in the liability for unrecognized tax benefits during the next twelve months will have a significant impact on our consolidated financial position or results of operations. We file income tax returns in the U.S. federal jurisdiction as well as many U.S. states and foreign jurisdictions. The tax years 2011 to 2013 remain open to examination by the major jurisdictions in which we are subject to tax. Fiscal years outside the normal statute of limitation remain open to audit by tax authorities due to tax attributes generated in those early years, which have been carried forward and may be audited in subsequent years when utilized.

Segment Information

Segment Information	12 Months Ended
	Jan. 31, 2016
Segment Reporting [Abstract]
Segment Information	Note 12. 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): Fiscal Year Ended January 31, 2014 2015 2016 United States $ 32,301 $ 134,920 $ 343,625 Rest of the world 10,432 39,531 96,708 Total revenue $ 42,733 $ 174,451 $ 440,333 Long-lived assets by geographic area are summarized as follows (in thousands): January 31, 2015 2016 United States $ 39,069 $ 50,501 Rest of the world 790 2,128 Total long-lived assets $ 39,859 $ 52,629

401 (k) Plan

401 (k) Plan	12 Months Ended
	Jan. 31, 2016
Compensation Related Costs [Abstract]
401 (k) Plan	Note 13. 401(k) Plan We have a 401(k) savings plan (“the 401(k) plan”) which qualifies as a deferred salary arrangement under section 401(k) of the Internal Revenue Code. Under the 401(k) plan, participating employees may elect to contribute up to 100% of their eligible compensation, subject to certain limitations. We have not made any matching contributions to date.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Jan. 31, 2016
Related Party Transactions [Abstract]
Related Party Transactions	Note 14. Related Party Transactions Certain members of our board of directors are executive officers of our customers. During the fiscal years ended January 31, 2014, 2015 and 2016, we recognized revenue of $165,000, $2.1 million and $6.2 million, respectively, from sales transactions to these customers. We purchased $420,000 and $728,000 of products and related services from two of these customers during the fiscal years ended January 31, 2015 and 2016.

Basis of Presentation and Sum22

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Jan. 31, 2016
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of Pure Storage, Inc. and our wholly owned subsidiaries and have been prepared in conformity with accounting principles generally accepted in the United States (U.S. GAAP). All intercompany balances and transactions have been eliminated in consolidation.
Stock Split	Stock Split In November 2013, we effected a 2-for-1 stock split. All references to common stock and convertible preferred stock shares and per share amounts including options to purchase common stock have been retroactively restated to reflect this stock split.
Foreign Currency	Foreign Currency The functional currency of our foreign subsidiaries is the U.S. dollar. Transactions denominated in currencies other than the functional currency are remeasured to the functional currency at the average exchange rate in effect during the period. At the end of each reporting period, monetary assets and liabilities are remeasured using exchange rates in effect at the balance sheet date. Non-monetary assets and liabilities are remeasured at historical exchange rates. Foreign currency transaction gains and losses are recorded in other income (expense), net in the consolidated statements of operations. For the fiscal years ended January 31, 2014, 2015 and 2016, we recorded net foreign currency transaction losses of $16,000, $648,000, and $2.3 million, respectively.
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-deliverable 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.
Concentration Risk	Concentration Risk Financial instruments that are exposed to concentration of credit risk consist primarily of cash and cash equivalents and accounts receivable. As of January 31, 2015 and 2016, substantially all of our cash and cash equivalents have been invested with one and three financial institutions, respectively, and such deposits exceed federally insured limits. Management believes that the financial institutions that hold our investments are financially sound and, accordingly, are subject to minimal credit risk. We define a customer as an end user that purchases our products and services from one of our channel partners or from us directly. Our revenue and accounts receivable are derived substantially from the United States across a multitude of industries. We perform ongoing evaluations to determine customer credit. As of January 31, 2015, we had one channel partner that individually represented 13% of total accounts receivable on that date. As of January 31, 2016, we had two channel partners that each individually represented 11% of total accounts receivable on that date. No single channel partner or customer represented over 10% of revenue for the fiscal years ended January 31, 2014, 2015 and 2016. We rely on a limited number of suppliers for our contract manufacturing and certain raw material components. In instances where suppliers fail to perform their obligations, we may be unable to find alternative suppliers or satisfactorily deliver our products to our customers on time.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of cash in banks and highly liquid investments, primarily money market funds, purchased with an original maturity of three months or less.
Restricted Cash	Restricted Cash Restricted cash is comprised of certificates of deposit related to our leases. As of January 31, 2015 and 2016, we had restricted cash of $4.6 million and $7.1 million, respectively, which was included in other long-term assets in the consolidated balance sheets.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying value of our financial instruments, including cash equivalents, accounts receivable, accounts payable and accrued liabilities, approximates fair value.
Accounts Receivable and Allowance	Accounts Receivable and Allowance Accounts receivable are recorded at the invoiced amount, and stated at realizable value, net of an allowance for doubtful accounts. Credit is extended to customers based on an evaluation of their financial condition and other factors. We generally do not require collateral or other security to support accounts receivable. We perform ongoing credit evaluations of our customers and maintain an allowance for doubtful accounts. We assess the collectability of the accounts by taking into consideration the aging of our trade receivables, historical experience, and management judgment. We write off trade receivables against the allowance when management determines a balance is uncollectible and no longer actively pursues collection of the receivable. The following table presents the changes in the allowance for doubtful accounts: Fiscal Year Ended January 31, 2014 2015 2016 (in thousands) Allowance for doubtful accounts, beginning balance $ 0 $ 160 $ 210 Provision 160 50 918 Writeoffs — — (184 ) Allowance for doubtful accounts, ending balance $ 160 $ 210 $ 944
Inventory	Inventory Inventory consists of finished goods and component parts, which are purchased from contract manufacturers. Product demonstration units, which we regularly sell, are the primary component of our inventories. Inventories are stated at the lower of cost or market. Cost is determined using the specific identification method for finished goods and weighted-average method for component parts. We account for excess and obsolete inventory by reducing the carrying value to the estimated net realizable value of the inventory based upon management’s assumptions about future demand and market conditions. In addition, we record a liability for firm, non-cancelable and unconditional purchase commitments with contract manufacturers and suppliers for quantities in excess of future demand forecasts consistent with excess and obsolete inventory valuations. Inventory write-offs were insignificant for the fiscal years ended January 31, 2014, 2015 and 2016.
Property and Equipment	Property and Equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization is computed using the straight-line method over the estimated useful lives of the respective assets (test equipment—2 years, computer equipment and software—2 to 3 years, furniture and fixtures—7 years). Leasehold improvements are amortized over the shorter of their estimated useful lives or the remaining lease term. Depreciation commences once the asset is placed in service.
Intangible Assets	Intangible Assets Intangible assets are stated at cost, net of accumulated amortization. During the fiscal year ended January 31, 2015, we acquired certain technology patents for $9.1 million. This amount is being amortized on a straight-line basis over an estimated useful life of seven years.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets We review our long-lived assets, including property and equipment, and finite-lived intangible assets for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. We measure the recoverability of these assets by comparing the carrying amounts to the future undiscounted cash flows the assets are expected to generate. If the total of the future undiscounted cash flows is less than the carrying amount of an asset, we record an impairment charge for the amount by which the carrying amount of the asset exceeds its fair market value. There have been no impairment charges recorded in any of the periods presented in the consolidated financial statements.
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 consolidated statements of operations. As of January 31, 2015 and 2016, we recorded short-term deferred commissions of $9.4 million and $15.7 million, respectively, and long-term deferred commissions of $7.5 million and $14.3 million, respectively, in other long-term assets in the consolidated balance sheets. During the fiscal years ended January 31, 2014, 2015 and 2016, we recognized sales commission expenses of $11.0 million, $27.7 million, and $47.2 million, respectively.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs, consisting of legal, accounting and filing fees directly related to our IPO, are capitalized. The deferred offering costs were offset against the IPO proceeds upon the completion of the offering.
Revenue Recognition	Revenue Recognition We derive revenue from two sources: (1) product revenue which includes hardware and embedded software and (2) support revenue which includes customer support, hardware maintenance and software upgrades on a when-and-if-available basis. We recognize revenue when: · Persuasive evidence of an arrangement exists —We rely upon sales agreements and/or purchase orders to determine the existence of an arrangement. · Delivery has occurred —We typically recognize product revenue upon shipment, as title and risk of loss are transferred to our channel partners at that time. Products are typically shipped directly by us to customers, and our channel partners do not stock our inventory. · The fee is fixed or determinable —We assess whether the fee is fixed or determinable based on the payment terms associated with the transaction. · Collection is reasonably assured —We assess collectability based on credit analysis and payment history. Our product revenue is derived from the sale of hardware and operating system software that is integrated into the hardware and therefore deemed essential to its functionality. The hardware and the operating system software essential to the functionality of the hardware are considered non-software deliverables and, therefore, are not subject to industry-specific software revenue recognition guidance. Support revenue is derived from the sale of maintenance and support agreements. Maintenance and support agreements include the right to receive unspecified software upgrades and enhancements on a when-and-if-available basis, bug fixes, parts replacement services related to the hardware, as well as access to our cloud-based management and support platform. Revenue related to maintenance and support agreements are recognized ratably over the contractual term, which generally range from one to three years. Costs related to maintenance and support agreements are expensed as incurred. In addition, our Forever Flash Most of our arrangements, other than stand-alone renewals of maintenance and support agreements, are multiple-element arrangements with a combination of product and support related deliverables (as defined above). Under multiple-element arrangements, we allocate consideration at the inception of an arrangement to all deliverables based on the relative selling price method in accordance with the hierarchy provided by the multiple-element arrangement accounting guidance, which includes (i) vendor-specific objective evidence (“VSOE”), of selling price, if available; (ii) third-party evidence (“TPE”), of selling price, if VSOE is not available; and (iii) best estimate of selling price (“BESP”), if neither VSOE nor TPE is available. As discussed below, because we have not established VSOE for any of our deliverables and TPE typically cannot be obtained, we typically allocate consideration to all deliverables based on BESP. · VSOE —We determine VSOE based on our historical pricing and discounting practices for the specific products and services when sold separately. In determining VSOE, we require that a substantial majority of the stand-alone selling prices fall within a reasonably narrow pricing range. We have not established VSOE for any of our hardware and support related deliverables given that our pricing is not sufficiently concentrated (based on an analysis of separate sales of the deliverables) to conclude that we can demonstrate VSOE of selling prices. · TPE —When VSOE cannot be established for deliverables in multiple-element arrangements, we apply judgment with respect to whether we can establish a selling price based on TPE. TPE is determined based on competitor prices for interchangeable products or services when sold separately to similarly situated customers. However, because our products contain a significant element of proprietary technology and our solutions offer substantially different features and functionality, the comparable pricing of products with similar functionality typically cannot be obtained. · BESP —When neither VSOE nor TPE can be established, we utilize BESP to allocate consideration to deliverables in a multiple-element arrangement. Our process to determine BESP for products and support is based on qualitative and quantitative considerations of multiple factors, which primarily include historical sales, margin objectives and discount behavior. Additional considerations are given to other factors such as customer demographics, costs to manufacture products or provide support, pricing practices and market conditions.
Deferred Revenue	Deferred Revenue Deferred revenue consists of amounts that have been invoiced but that have not yet been recognized as revenue and primarily consists of support. The current portion of deferred revenue represents the amounts that are expected to be recognized as revenue within one year of the consolidated balance sheet date.
Warranty Costs	Warranty Costs We generally provide a three-year warranty on hardware and a 90-day warranty on our software embedded in the hardware. Our hardware warranty provides for parts replacement for defective components and our software warranty provides for bug fixes. With respect to our hardware warranty obligation, we have a warranty agreement with our contract manufacturer under which our contract manufacturer is generally required to replace defective hardware within three years of shipment. Furthermore, our maintenance and support agreement provides for the same parts replacement that customers are entitled to under our warranty program, except that replacement parts are delivered according to targeted response times to minimize disruption to our customers’ critical business applications. Substantially all customers purchase maintenance and support agreements. Therefore, given the warranty agreement with our contract manufacturer and that substantially all our products sales are sold together with maintenance and support agreements, we generally do not have exposure related to warranty costs and no warranty reserve has been recorded.
Research and Development	Research and Development Research and development costs are expensed as incurred. Research and development costs consist primarily of personnel costs including stock-based compensation expense, expensed prototype, to the extent there is no alternative use for that equipment, consulting services, depreciation of equipment used in research and development and allocated overhead costs.
Software Development Costs	Software Development Costs We expense software development costs before technological feasibility is reached. We have determined that technological feasibility is reached shortly before the release of our products and as a result, the development costs incurred after the establishment of technological feasibility and before the release of those products have not been significant and accordingly, all software development costs have been expensed as incurred. Software development costs also include costs incurred related to our hosted applications used to deliver our support services. Capitalization begins when the preliminary project stage is complete, management with the relevant authority authorizes and commits to the funding of the software project, and it is probable the project will be completed and the software will be used to perform the intended function. Total costs related to our hosted applications incurred to date have been insignificant and as a result no software development costs were capitalized during the fiscal years ended January 31, 2014, 2015 and 2016.
Advertising Expenses	Advertising Expenses Advertising costs are expensed as incurred. Advertising expenses were $195,000, $1.4 million and $6.2 million for the fiscal years ended January 31, 2014, 2015 and 2016, respectively.
Stock-Based Compensation	Stock-Based Compensation We determine the fair value of our stock options under our equity plans and purchase rights issued to employees under our ESPP on the date of grant utilizing the Black-Scholes option pricing model, which is impacted by the fair value of our common stock, as well as changes in assumptions regarding a number of subjective variables. These variables include the expected common stock price volatility over the term of the awards, the expected term of the awards, risk-free interest rates and expected dividend yield. We recognize stock-based compensation expense for stock-based awards on a straight-line basis over the period during which an employee is required to provide services in exchange for the award (generally the vesting period of the award). Stock-based compensation expense is recognized only for those awards expected to vest. We estimate future forfeitures at the date of grant and revise the estimates, if necessary, in subsequent periods if actual forfeitures differ from those estimates. For stock-based awards granted to employees with a performance condition, we recognize stock-based compensation expense for these awards under the accelerated attribution method over the requisite service period when management determines it is probable that the performance condition will be satisfied. We determine the fair value of our stock options issued to non-employees on the date of grant utilizing the Black-Scholes option pricing model. Stock-based compensation expense for stock options issued to non-employees is recognized over the requisite service period or when it is probable that the performance condition will be satisfied. Options subject to vesting are periodically remeasured to current fair value over the vesting period.
Comprehensive Loss	Comprehensive Loss We did not have any other comprehensive income or loss during the periods presented and therefore comprehensive loss was the same as net loss.
Income Taxes	Income Taxes We account for income taxes using the asset and liability method. Deferred income taxes are recognized by applying enacted statutory tax rates applicable to future years to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. The measurement of deferred tax assets is reduced, if necessary, by a valuation allowance to amounts that are more likely than not to be realized. We recognize tax benefits from uncertain tax positions only if we believe that it is more likely than not that the tax position will be sustained on examination by the taxing authorities based on the technical merits of the position. The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50% likelihood of being realized upon settlement.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers Revenue from Contracts with Customers In November 2015, the FASB issued ASU No. 2015-17, Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842)
Reclassifications	Reclassifications As a result of the adoption of ASU 2015-17, we made the following reclassifications to the January 31, 2014 balance sheet: a $2.5 million decrease to non-current deferred tax assets, a $2.6 million decrease to current deferred tax liability, and an increase of $92,000 to non-current deferred tax liability, and to the January 31, 2015 balance sheet: a $5.5 million decrease to non-current deferred tax assets, a $5.8 million decrease to current deferred tax liability, and an increase of $300,000 to non-current deferred tax liability.

Basis of Presentation and Sum23

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Jan. 31, 2016
Accounting Policies [Abstract]
Schedule of Changes in Allowance for Doubtful Accounts	The following table presents the changes in the allowance for doubtful accounts: Fiscal Year Ended January 31, 2014 2015 2016 (in thousands) Allowance for doubtful accounts, beginning balance $ 0 $ 160 $ 210 Provision 160 50 918 Writeoffs — — (184 ) Allowance for doubtful accounts, ending balance $ 160 $ 210 $ 944

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Jan. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis	The following tables set forth the fair value of our financial assets measured at fair value on a recurring basis as of January 31, 2015 and 2016 using the above input categories (in thousands): January 31, 2015 Level I Level II Level III Total Financial Assets: Cash and cash equivalents: Money market funds $ 190,621 $ — $ — $ 190,621 Restricted cash: Certificates of deposit — 4,648 — 4,648 Total assets measured at fair value $ 190,621 $ 4,648 $ — $ 195,269 January 31, 2016 Level I Level II Level III Total Financial Assets: Cash and cash equivalents: Money market funds $ 45,614 $ — $ — $ 45,614 Restricted cash: Certificates of deposit — 7,132 — 7,132 Total assets measured at fair value $ 45,614 $ 7,132 $ — $ 52,746

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Jan. 31, 2016
Balance Sheet Components Disclosure [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net consists of the following (in thousands): January 31, 2015 2016 Test equipment $ 37,059 $ 65,663 Computer equipment and software 19,022 31,388 Furniture and fixtures 2,460 2,852 Leasehold improvements 3,776 4,935 Total property and equipment 62,317 104,838 Less: accumulated depreciation and amortization (22,458 ) (52,209 ) Property and equipment, net $ 39,859 $ 52,629
Schedule of Intangible Assets, Net	Intangible assets, net consist of the following (in thousands): January 31, 2015 2016 Technology patents $ 9,125 $ 9,125 Accumulated amortization (841 ) (2,145 ) Intangible assets, net $ 8,284 $ 6,980
Schedule of Expected Amortization Expenses for Intangible Assets	As of January 31, 2016, expected amortization expense for intangible assets for each of the next five years and thereafter is as follows (in thousands): Fiscal Year Ending January 31, Estimated Amortization Expense 2017 $ 1,304 2018 1,304 2019 1,304 2020 1,304 2021 1,304 Thereafter 460 Total $ 6,980
Schedule of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following (in thousands): January 31, 2015 2016 Sales and use tax payable $ 591 $ 299 Accrued professional fees 1,502 3,044 Accrued travel and entertainment expenses 1,138 2,182 Income tax payable 779 1,791 Other accrued liabilities 2,096 6,760 Total accrued expenses and other liabilities $ 6,106 $ 14,076

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Jan. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Schedule Aggregate Future Minimum Payments Under Non-Cancelable Operating Leases	As of January 31, 2016, the aggregate future minimum payments under non-cancelable operating leases consist of the following (in thousands): Fiscal Year Ending January 31, Operating Leases 2017 $ 14,402 2018 14,976 2019 10,637 2020 8,534 2021 5,477 Thereafter 6,728 Total $ 60,754

Convertible Preferred Stock (Ta

Convertible Preferred Stock (Tables)	12 Months Ended
	Jan. 31, 2016
Temporary Equity [Abstract]
Summary of Convertible Preferred Stock Outstanding	Convertible preferred stock outstanding as of January 31, 2015 and as of immediately prior to the conversion into Class B common stock consisted of the following (in thousands, except share data): Convertible Preferred Stock: Shares Authorized Shares Issued and Outstanding Aggregate Liquidation Preference Net Proceeds Series A 24,360,000 24,360,000 $ 5,075 $ 5,038 Series B 30,211,506 30,211,506 20,000 19,925 Series C 14,253,774 14,253,774 30,444 30,346 Series D 10,584,066 10,584,066 39,916 39,828 Series E 24,761,984 24,761,984 171,637 168,283 Series F 15,897,337 14,307,603 225,000 220,803 Series F-1 3,811,285 3,801,746 59,786 59,717 Total convertible preferred stock 123,879,952 122,280,679 $ 551,858 $ 543,940

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Jan. 31, 2016
Equity [Abstract]
Summary of Reserved Shares of Common Stock for Future Issuance	As of January 31, 2016, we had reserved shares of common stock for future issuance as follows: January 31, 2016 Shares underlying outstanding stock options 68,879,087 Shares reserved for future equity awards 25,337,800 Shares reserved for future employee stock purchase plan awards 3,500,000 Total 97,716,887

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	12 Months Ended
	Jan. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity Under Equity Incentive Plans and Related Information	A summary of 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 (Years) Aggregate Intrinsic Value (in thousands) Balance as of January 31, 2015 54,284,474 $ 3.02 8.3 $ 523,654 Options granted 19,269,524 15.76 Options exercised (2,313,598 ) 2.58 Options cancelled (2,361,313 ) 7.96 Balance as of January 31, 2016 68,879,087 $ 6.43 7.9 $ 505,131 Vested and exercisable as of January 31, 2016 24,297,716 $ 2.04 6.7 $ 267,213 Vested and expected to vest as of January 31, 2016 66,945,857 $ 6.37 7.9 $ 494,544
Summary of Estimate Fair Value of Employee Stock Options and Employee Purchase Plan	We estimate the fair value of employee stock options and ESPP purchase rights using a Black-Scholes option pricing model with the following assumptions: Fiscal Year Ended January 31, 2014 2015 2016 Employee Stock Options Expected term (in years) 5.3 - 7.3 5.0 - 6.9 6.0 - 7.4 Expected volatility 65% - 69% 55% - 68% 48%-52% Risk-free interest rate 0.8% - 2.1% 1.3% - 2.2% 1.5%-1.9% Dividend rate — — — Fair value of common stock $1.46 - $2.98 $4.81 - $12.65 $13.94-$19.68 Employee Stock Purchase Plan Expected term (in years) — — 0.4 - 1.9 Expected volatility — — 49% Risk-free interest rate — — 0.1% - 0.7% Dividend rate — — —
Summary of Estimate Fair Value of Non-employee Stock	We estimate the fair value of non-employee stock options on the date of grant using a Black-Scholes option pricing model with the following assumptions: Fiscal Year Ended January 31, 2014 2015 2016 Expected term (in years) 10.0 10.0 10.0 Expected volatility 62% - 65% 62% - 63% 49% Risk-free interest rate 1.1% - 2.6% 1.6% - 2.6% 1.5% Dividend rate — — — Fair value of common stock $1.79 - $2.98 $9.40 - $12.40 $ 17.00
Summarizes the Components of Stock-Based Compensation	The following table summarizes the components of stock-based compensation expense recognized in the consolidated statements of operations (in thousands): Fiscal Year Ended January 31, 2014 2015 2016 Cost of revenue—product $ 253 $ 303 $ 276 Cost of revenue—support 316 1,273 2,388 Research and development 11,477 22,512 31,135 Sales and marketing 9,014 22,466 16,966 General and administrative 506 6,479 7,460 Total stock-based compensation $ 21,566 $ 53,033 $ 58,225

Net Loss per Share Attributab30

Net Loss per Share Attributable to Common Stockholders (Tables)	12 Months Ended
	Jan. 31, 2016
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): Fiscal Year Ended January 31, 2014 2015 2016 Net loss $ (78,561 ) $ (183,231 ) (213,752 ) Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted 24,237 27,925 82,460 Net loss per share attributable to common stockholders, basic and diluted $ (3.24 ) $ (6.56 ) $ (2.59 )
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): Fiscal Year Ended January 31, 2014 2015 2016 Convertible preferred stock (on an if-converted basis) 90,103 117,794 — Stock options to purchase common stock 33,715 50,429 61,795 Early exercised stock options and restricted stock awards 9,768 8,047 3,618 Employee stock purchase plan — — 170 Total 133,586 176,270 65,583

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Jan. 31, 2016
Income Tax Disclosure [Abstract]
Schedule of Geographical Breakdown of Income (Loss) before Provision for Income Taxes	The geographical breakdown of income (loss) before provision for income taxes is as follows (in thousands): Fiscal Year Ended January 31, 2014 2015 2016 Domestic $ (79,588 ) $ (186,922 ) $ (195,019 ) International 1,318 5,028 (17,164 ) Total $ (78,270 ) $ (181,894 ) $ (212,183 )
Schedule of Components of Provision for Income Taxes	The components of the provision for income taxes are as follows (in thousands): Fiscal Year Ended January 31, 2014 2015 2016 Current: State 37 56 210 Foreign 162 1,073 2,198 Total 199 1,129 2,408 Deferred: Foreign 92 208 (839 ) Total provision for income taxes $ 291 $ 1,337 $ 1,569
Reconciliation of the Federal Statutory Income Tax Rate and Effective Income Tax Rate	The reconciliation of the federal statutory income tax rate and effective income tax rate is as follows: Fiscal Year Ended January 31, 2014 2015 2016 (in Tax at federal statutory rate $ (26,611 ) $ (61,844 ) $ (72,142 ) State tax, net of federal benefit 32 44 152 Stock-based compensation expense 1,570 5,328 10,866 Research and development tax credits (1,036 ) (1,999 ) (3,832 ) Foreign rate differential (194 ) (429 ) 7,106 Change in valuation allowance 26,152 60,042 58,979 Other 378 195 440 Provision for income taxes $ 291 $ 1,337 $ 1,569
Significant Components of Deferred Tax Assets and Liabilities	The significant component of our deferred tax assets and liabilities were as follows: January 31, 2015 2016 (in thousands) Deferred tax assets: Net operating loss carryforwards $ 101,815 $ 137,456 Tax credit carryover 6,136 12,406 Accruals and reserves 729 1,921 Deferred revenue 3,538 20,314 Stock-based compensation expense 4,258 12,588 Depreciation and amortization 2,054 3,397 Charitable contribution carryforwards — 4,380 Total deferred tax assets 118,530 192,462 Deferred tax liabilities: Deferred commissions (5,924 ) (11,000 ) Total deferred tax liabilities (5,924 ) (11,000 ) Valuation allowance (112,906 ) (180,926 ) Net deferred tax assets (liabilities), net of valuation allowance $ (300 ) $ 536
Summary of Activity Related to Unrecognized Tax Benefits	The activity related to the unrecognized tax benefits is as follows: Fiscal Year Ended January 31, 2014 2015 2016 (in thousands) Gross unrecognized tax benefits—beginning balance $ 479 $ 4,676 $ 13,874 Decreases related to tax positions taken during prior years (10 ) — (3,969 ) Increases related to tax positions taken during prior years — — 35 Increases related to tax positions taken during current year 4,207 9,198 5,530 Gross unrecognized tax benefits—ending balance $ 4,676 $ 13,874 $ 15,470

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Jan. 31, 2016
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): Fiscal Year Ended January 31, 2014 2015 2016 United States $ 32,301 $ 134,920 $ 343,625 Rest of the world 10,432 39,531 96,708 Total revenue $ 42,733 $ 174,451 $ 440,333
Schedule of Long-Lived Assets by Geographic Area	Long-lived assets by geographic area are summarized as follows (in thousands): January 31, 2015 2016 United States $ 39,069 $ 50,501 Rest of the world 790 2,128 Total long-lived assets $ 39,859 $ 52,629

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	Mar. 15, 2016USD ($)	Jan. 31, 2016USD ($)Patent	Jan. 31, 2015USD ($)	Jan. 31, 2014USD ($)
Commitments And Contingencies [Line Items]
Reasonably possible loss contingency, maximum		$ 14,000,000
Lease expiration period		2025-12
Rent expense recognized under operating leases		$ 11,000,000	$ 7,500,000	$ 1,800,000
Non-cancelable purchase obligation related to software services		5,900,000	626,000,000
Outstanding letters of credit		$ 7,100,000	4,600,000
Letter of credit maturity year and month		2023-03
Loss contingency		$ 0	$ 0
Subsequent Event
Commitments And Contingencies [Line Items]
Royalty damages	$ 14,000,000
Patent Infringement
Commitments And Contingencies [Line Items]
Patent infringement allegations number | Patent		5

Business Overview - Additional

Business Overview - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Oct. 31, 2015	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Organization And Description Of Business [Line Items]
Net proceeds from initial public offering		$ 459,425	$ 0	$ 0
Conversion of preferred stock	122,280,679
IPO
Organization And Description Of Business [Line Items]
Net proceeds from initial public offering	$ 459,400
Underwriting discounts and commissions	29,300
Offering costs incurred	$ 4,500
IPO | Class A Common Stock
Organization And Description Of Business [Line Items]
Shares issued	28,750,000
Issue price per share	$ 17
IPO | Class B Common Stock
Organization And Description Of Business [Line Items]
Conversion of preferred stock	122,280,679

Basis of Presentation and Sum35

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)	1 Months Ended	12 Months Ended
	Nov. 30, 2013	Jan. 31, 2016USD ($)Customer	Jan. 31, 2015USD ($)Customer	Jan. 31, 2014USD ($)Customer
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Stock split ratio	2
Net foreign currency transaction losses		$ (2,300,000)	$ (648,000)	$ (16,000)
Restricted cash		7,100,000	4,600,000
Acquisition of intangible assets		0	9,125,000	0
Impairment charges		0	0	0
Deferred commissions, current		15,703,000	9,431,000
Deferred income taxes, non-current		14,300,000	7,500,000
Sales commission expenses		$ 47,200,000	27,700,000	11,000,000
Period required with included controller refresh to have additional maintenance and support renewal		3 years
Additional maintenance and support period		3 years
Warranty reserve		$ 0
Capitalization of software development cost		0	0	0
Advertising expenses		6,200,000	1,400,000	195,000
Other comprehensive income (loss)		$ 0	0	0
New Accounting Pronouncement Early Adoption Effect
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Decrease in non-current deferred tax assets			(5,500,000)	(2,500,000)
Decrease in current deferred tax liability			(5,800,000)	(2,600,000)
Increase in non-current deferred tax liability			300,000	$ 92,000
Hardware
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Standard product warranty period		3 years
Embedded Software
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Standard product warranty period		90 days
Technology Patents
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Acquisition of intangible assets			$ 9,100,000
Estimated useful life of intangible assets			7 years
Minimum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Contractual term		1 year
Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Contractual term		3 years
Test Equipment
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life		2 years
Computer, Equipment and Software | Minimum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life		2 years
Computer, Equipment and Software | Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life		3 years
Furniture and Fixtures
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life		7 years
Leasehold Improvements
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life		shorter of their estimated useful lives or the remaining lease term
Accounts Receivable
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of major channel partner or customer | Customer		2	1
Accounts Receivable | Customer Concentration Risk
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		11.00%	13.00%
Sales Revenue Net
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of major channel partner or customer | Customer		0	0	0

Basis of Presentation and Sum36

Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Changes in Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Receivables [Abstract]
Allowance for doubtful accounts, beginning balance	$ 210	$ 160	$ 0
Provision	918	50	160
Writeoffs	(184)	0	0
Allowance for doubtful accounts, ending balance	$ 944	$ 210	$ 160

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 52,746	$ 195,269
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	45,614	190,621
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	7,132	4,648
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	45,614	190,621
Money Market Funds | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	45,614	190,621
Money Market Funds | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Money Market Funds | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Certificates of Deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	7,132	4,648
Certificates of Deposit | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	0	0
Certificates of Deposit | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	7,132	4,648
Certificates of Deposit | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets measured at fair value	$ 0	$ 0

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 104,838	$ 62,317
Less: accumulated depreciation and amortization	(52,209)	(22,458)
Property and equipment, net	52,629	39,859
Test Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	65,663	37,059
Computer, Equipment and Software
Property Plant And Equipment [Line Items]
Total property and equipment, gross	31,388	19,022
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment, gross	2,852	2,460
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 4,935	$ 3,776

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($)	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Balance Sheet Components Disclosure [Abstract]
Depreciation and amortization	$ 31,000,000	$ 14,600,000	$ 4,400,000
Intangible assets amortization expense	$ 1,300,000	$ 841,000	$ 0

Balance Sheet Components - Sc40

Balance Sheet Components - Schedule of Intangible Assets, Net (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Finite Lived Intangible Assets [Line Items]
Intangible assets, net	$ 6,980	$ 8,284
Technology Patents
Finite Lived Intangible Assets [Line Items]
Technology patents	9,125	9,125
Accumulated amortization	(2,145)	(841)
Intangible assets, net	$ 6,980	$ 8,284

Balance Sheet Components - Sc41

Balance Sheet Components - Schedule of Expected Amortization Expenses for Intangible Assets (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Intangible Assets Net Disclosure [Abstract]
2,017	$ 1,304
2,018	1,304
2,019	1,304
2,020	1,304
2,021	1,304
Thereafter	460
Intangible assets, net	$ 6,980	$ 8,284

Balance Sheet Components - Sc42

Balance Sheet Components - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Payables And Accruals [Abstract]
Sales and use tax payable	$ 299	$ 591
Accrued professional fees	3,044	1,502
Accrued travel and entertainment expenses	2,182	1,138
Income tax payable	1,791	779
Other accrued liabilities	6,760	2,096
Total accrued expenses and other liabilities	$ 14,076	$ 6,106

Commitments and Contingencies43

Commitments and Contingencies - Aggregate Future Minimum Payments Under Non-Cancelable Operating Leases (Details) $ in Thousands	Jan. 31, 2016USD ($)
Commitments And Contingencies Disclosure [Abstract]
2,017	$ 14,402
2,018	14,976
2,019	10,637
2,020	8,534
2,021	5,477
Thereafter	6,728
Aggregate future minimum payments under non-cancelable operating leases	$ 60,754

Line of Credit - Additional Inf

Line of Credit - Additional Information (Details) - USD ($)	1 Months Ended
	Aug. 31, 2014	Jan. 31, 2016	Jan. 31, 2015
Debt Instrument [Line Items]
Line of credit		$ 0	$ 0
Revolving Line of Credit
Debt Instrument [Line Items]
Line of credit facility, term	2 years
Line of credit facility, maximum borrowing capacity	$ 15,000,000
Percentage of accounts receivable qualifying for revolving credit agreement	80.00%
Line of credit facility expiration month and year	2016-08
Line of credit facility, termination fee on or after first year	$ 150,000
Revolving Line of Credit | Prime Rate
Debt Instrument [Line Items]
Line of credit facility, interest rate	1.00%

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Details)	Oct. 31, 2015shares
Class Of Stock Disclosures [Abstract]
Conversion of preferred stock	122,280,679

Convertible Preferred Stock - S

Convertible Preferred Stock - Summary of Convertible Preferred Stock Outstanding (Detail) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized	0	123,879,952
Convertible preferred stock, shares issued	0	122,280,679
Convertible preferred stock, shares outstanding	0	122,280,679	104,106,000	79,409,000
Convertible preferred stock, aggregate liquidation preference	$ 0	$ 551,858
Convertible preferred stock, net proceeds	$ 0	$ 543,940	$ 262,970	$ 95,137
Series A Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		24,360,000
Convertible preferred stock, shares issued		24,360,000
Convertible preferred stock, shares outstanding		24,360,000
Convertible preferred stock, aggregate liquidation preference		$ 5,075
Convertible preferred stock, net proceeds		$ 5,038
Series B Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		30,211,506
Convertible preferred stock, shares issued		30,211,506
Convertible preferred stock, shares outstanding		30,211,506
Convertible preferred stock, aggregate liquidation preference		$ 20,000
Convertible preferred stock, net proceeds		$ 19,925
Series C Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		14,253,774
Convertible preferred stock, shares issued		14,253,774
Convertible preferred stock, shares outstanding		14,253,774
Convertible preferred stock, aggregate liquidation preference		$ 30,444
Convertible preferred stock, net proceeds		$ 30,346
Series D Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		10,584,066
Convertible preferred stock, shares issued		10,584,066
Convertible preferred stock, shares outstanding		10,584,066
Convertible preferred stock, aggregate liquidation preference		$ 39,916
Convertible preferred stock, net proceeds		$ 39,828
Series E Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		24,761,984
Convertible preferred stock, shares issued		24,761,984
Convertible preferred stock, shares outstanding		24,761,984
Convertible preferred stock, aggregate liquidation preference		$ 171,637
Convertible preferred stock, net proceeds		$ 168,283
Series F Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		15,897,337
Convertible preferred stock, shares issued		14,307,603
Convertible preferred stock, shares outstanding		14,307,603
Convertible preferred stock, aggregate liquidation preference		$ 225,000
Convertible preferred stock, net proceeds		$ 220,803
Series F-1 Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		3,811,285
Convertible preferred stock, shares issued		3,801,746
Convertible preferred stock, shares outstanding		3,801,746
Convertible preferred stock, aggregate liquidation preference		$ 59,786
Convertible preferred stock, net proceeds		$ 59,717

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Jan. 31, 2016USD ($)Vote$ / sharesshares	Oct. 31, 2015shares	Sep. 30, 2015shares	Jan. 31, 2015$ / sharesshares
Class Of Stock [Line Items]
Preferred stock, shares authorized	20,000,000	20,000,000		0
Preferred stock, shares issued	0			0
Preferred stock, shares outstanding	0			0
Common stock, shares authorized	2,250,000,000			230,812,000
Common stock, shares issued	190,509,000			36,465,000
Common stock, shares outstanding	190,509,000			36,465,000
Common stock, voting rights	The rights of the holders of Class A and Class B common stock are identical, except with respect to voting. Each share of Class A common stock is entitled to one vote per share. Each share of Class B common stock is entitled to 10 votes per share.
Common stock, conversion features	Shares of Class B common stock may be converted to Class A common stock at any time at the option of the stockholder. Shares of Class B common stock automatically convert to Class A common stock upon the following: (i) sale or transfer of such share of Class B common stock; (ii) the death of the Class B common stockholder (or nine months after the date of death if the stockholder is one of our founders); and (iii) on the final conversion date, defined as the earlier of (a) the first trading day on or after the date on which the outstanding shares of Class B common stock represent less than 10% of the then outstanding Class A and Class B common stock; (b) the tenth anniversary of the IPO; or (c) the date specified by vote of the holders of a majority of the outstanding shares of Class B common stock, voting as a single class.
Class A Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized	2,000,000,000			1,000
Common stock, par value per share | $ / shares	$ 0.0001			$ 0.0001
Common stock, shares issued	28,769,572			0
Common stock, shares outstanding	28,769,572			0
Common stock, entitled votes per share | Vote	1
Class B Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized	250,000,000			230,811,000
Common stock, par value per share | $ / shares	$ 0.0001			$ 0.0001
Common stock, shares issued	161,739,883			36,465,000
Common stock, shares outstanding	161,739,883			36,465,000
Common stock, entitled votes per share | Vote	10
Class B Common Stock | Pure Good Foundation
Class Of Stock [Line Items]
Common stock, shares issued			700,000
Non cash general and administrative expense | $	$ 11.9

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Reserved Shares of Common Stock for Future Issuance (Details) - shares	Jan. 31, 2016	Jan. 31, 2015
Class Of Stock [Line Items]
Shares underlying outstanding stock options	68,879,087	54,284,474
Shares reserved of common stock for future issuance	97,716,887
Employee Stock Purchase Plan
Class Of Stock [Line Items]
Shares reserved of common stock for future issuance	3,500,000
Equity Awards
Class Of Stock [Line Items]
Shares reserved of common stock for future issuance	25,337,800

Equity Incentive Plans - Additi

Equity Incentive Plans - Additional Information (Details)	Jul. 31, 2014USD ($)shares	Nov. 30, 2013USD ($)shares	Aug. 31, 2015USD ($)shares	Jan. 31, 2016USD ($)Plan$ / sharesshares	Jan. 31, 2015USD ($)$ / sharesshares	Jan. 31, 2014USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of equity incentive plans | Plan				2
Shares reserved for future issuance | shares				97,716,887
Fair market value of Class A common stock				$ 455,138,000
Issuance of common stock upon exercise of stock options (in shares) | shares				2,313,598
Promissory note amount outstanding					$ 4,000,000
Issuance of common stock upon exercise of stock options						$ 336,000
Unrecognized compensation cost				$ 201,800,000
Unrecognized compensation cost related to stock awards, weighted-average period				3 years 8 months 12 days
Stock-based compensation expense				$ 58,225,000	$ 53,033,000	$ 21,566,000
Number of options granted | shares				19,269,524
Payment for repurchase of common stock and vested stock options	$ 57,700,000	$ 20,500,000
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair market value of Class A common stock				$ 3,000
Issuance of common stock upon exercise of stock options (in shares) | shares						4,047,000
Unvested stock option, common stock repurchased during the period | shares					3,803,000	3,046,000
Issuance of common stock upon exercise of stock options						$ 0
Repurchase of shares | shares	735,426	1,442,098
Accumulated Deficit
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair market value of Class A common stock				$ 0
Issuance of common stock upon exercise of stock options						0
Repurchase of recorded in accumulated deficit	$ 30,100,000	$ 7,200,000
Tender Offer
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from stock options exercised	$ 2,100,000	$ 640,000
Repurchase Of Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense					$ 27,600,000	$ 13,300,000
Promissory Notes
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock upon exercise of stock options (in shares) | shares						6,295,056
Fixed interest rate ,minimum				0.95%
Fixed interest rate ,maximum				1.84%
Promissory note amount outstanding						$ 3,200,000
Nonrecourse Promissory Note
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock upon exercise of stock options (in shares) | shares					300,000
Issuance of common stock upon exercise of stock options					$ 773,000
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance | shares				25,337,800
Intrinsic value of exercised options				$ 29,500,000	$ 43,200,000	$ 8,500,000
Weighted-average grant date fair value of options granted | $ / shares				$ 8.38	$ 5.71	$ 1.50
Total grant date fair value of options vested				$ 35,400,000	$ 9,900,000	$ 3,500,000
Repurchase of shares | shares	3,067,910	1,603,536
Employee Stock Option | Early Exercise of Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock upon exercise of stock options (in shares) | shares				0	642,248
Proceeds from stock options exercised					$ 1,900,000
Unvested stock option, common stock repurchased during the period | shares				15,000	50,000
Common stock subject to repurchase | shares				2,809,264	4,710,454
Common stock subject to repurchase, aggregate price				$ 4,800,000	$ 6,500,000
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options granted, net of cancellations | shares				238,000	499,750	3,883,654
Stock-based compensation expense				$ 2,500,000	$ 1,700,000	$ 596,000
Non Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense				$ 3,100,000	$ 2,500,000	$ 1,100,000
Number of options granted | shares				22,500	83,500	1,126,400
Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity awards of vest period				4 years
Common Stock Shares Issued | shares				18,300,000
Weighted-average grant date fair market value | $ / shares				$ 0.0005
Share-based compensation, number of shares vested | shares						2,812,500
2015 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity awards of vest expire period				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 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserved for future issuance | shares				3,500,000
Employee stock purchase plan offering period			24 months
Fair market value of Class A common stock			$ 17
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense				$ 4,400,000
Unrecognized stock-based compensation expense				$ 21,600,000
Stock-based Compensation Expense Related to Tender Offer
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 27,600,000	$ 13,300,000
Class A Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Closing price of stock | $ / shares				$ 13.01
Class A Common Stock | 2015 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares initially reserved for issuance | shares				27,000,000
Increase in shares reserved by percentage of capital stock				5.00%
Shares reserved for future issuance | shares				25,337,800
Class A Common Stock | 2015 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price as percentage of fair market value of common stock			85.00%
Shares reserved for future issuance | shares			3,500,000
Payroll deductions percentage			30.00%
Share cap for ESPP at purchase date | shares			3,000
Calendar year gap for ESPP contribution amount			$ 25,000

Equity Incentive Plans - Summar

Equity Incentive Plans - Summary of Activity Under the Equity Incentive Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015
Options Outstanding, Number of Shares
Options Outstanding, Number of Shares, Beginning Balance	54,284,474
Options Outstanding, Number of Shares, Options granted	19,269,524
Options Outstanding, Number of Shares, Options exercised	(2,313,598)
Options Outstanding, Number of Shares, Options cancelled	(2,361,313)
Options Outstanding, Number of Shares, Ending Balance	68,879,087	54,284,474
Options Outstanding, Number of Shares, Vested and exercisable	24,297,716
Options Outstanding, Number of Shares, Vested and expected to vest	66,945,857
Options Outstanding, Weighted Average Exercise Price
Weighted Average Exercise Price, Beginning Balance	$ 3.02
Weighted Average Exercise Price, Options granted	15.76
Weighted Average Exercise Price, Options exercised	2.58
Weighted Average Exercise Price, Options Cancelled	7.96
Weighted Average Exercise Price, Ending Balance	6.43	$ 3.02
Weighted Average Exercise Price, Vested and exercisable	2.04
Weighted Average Exercise Price, Vested and expected to vest	$ 6.37
Options Outstanding, Weighted Average Remaining Contractual Life (Years)
Weighted Average Remaining Contractual Life (Years)	7 years 10 months 24 days	8 years 3 months 18 days
Weighted Average Remaining Contractual Life (Years), Vested and exercisable	6 years 8 months 12 days
Weighted Average Remaining Contractual Life (Years), Vested and expected to vest	7 years 10 months 24 days
Options Outstanding, Aggregate Intrinsic Value
Aggregate Intrinsic Value	$ 505,131	$ 523,654
Aggregate Intrinsic Value, Vested and exercisable	267,213
Aggregate Intrinsic Value, Vested and expected to vest	$ 494,544

Equity Incentive Plans - Summ51

Equity Incentive Plans - Summary of Estimate Fair Value of Employee Stock Options and Employee Purchase Plan (Details) - $ / shares	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected volatility, Minimum	48.00%	55.00%	65.00%
Expected volatility, Maximum	52.00%	68.00%	69.00%
Risk-free interest rate, Minimum	1.50%	1.30%	0.80%
Risk-free interest rate, Maximum	1.90%	2.20%	2.10%
Dividend rate	0.00%	0.00%	0.00%
Employee Stock Option | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years	5 years	5 years 3 months 18 days
Fair value of common stock	$ 13.94	$ 4.81	$ 1.46
Employee Stock Option | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	7 years 4 months 24 days	6 years 10 months 24 days	7 years 3 months 18 days
Fair value of common stock	$ 19.68	$ 12.65	$ 2.98
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, Minimum	0.10%	0.00%	0.00%
Risk-free interest rate, Maximum	0.70%	0.00%	0.00%
Dividend rate	0.00%	0.00%	0.00%
Expected volatility	49.00%	0.00%	0.00%
ESPP | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	4 months 24 days	0 years	0 years
ESPP | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	1 year 10 months 24 days	0 years	0 years

Equity Incentive Plans - Summ52

Equity Incentive Plans - Summary of Estimate Fair Value of Non-Employee Stock (Details) - Non-Employee Stock Option Awards - $ / shares	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	10 years	10 years	10 years
Expected volatility, Minimum		62.00%	62.00%
Expected volatility	49.00%
Expected volatility, Maximum		63.00%	65.00%
Risk-free interest rate, Minimum		1.60%	1.10%
Risk-free interest rate	1.50%
Risk-free interest rate, Maximum		2.60%	2.60%
Dividend rate	0.00%	0.00%	0.00%
Fair value of common stock	$ 17
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock		$ 9.40	$ 1.79
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock		$ 12.40	$ 2.98

Equity Incentive Plans - Summ53

Equity Incentive Plans - Summary of Stock-Based Compensation Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 58,225	$ 53,033	$ 21,566
Cost of Revenue Product
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	276	303	253
Cost of Revenue Support
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	2,388	1,273	316
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	31,135	22,512	11,477
Sales and Marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	16,966	22,466	9,014
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 7,460	$ 6,479	$ 506

Net Loss per Share Attributab54

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	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Earnings Per Share [Abstract]
Net loss	$ (213,752)	$ (183,231)	$ (78,561)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	82,460	27,925	24,237
Net loss per share attributable to common stockholders, basic and diluted	$ (2.59)	$ (6.56)	$ (3.24)

Net Loss per Share Attributab55

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	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount	65,583	176,270	133,586
Convertible preferred stock (on an if-converted basis)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount	0	117,794	90,103
Equity Awards
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount	61,795	50,429	33,715
Early exercised stock options and restricted stock awards
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount	3,618	8,047	9,768
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	170	0	0

Income Taxes - Schedule of Geog

Income Taxes - Schedule of Geographical Breakdown of Income (Loss) before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Income Tax Disclosure [Abstract]
Domestic	$ (195,019)	$ (186,922)	$ (79,588)
International	(17,164)	5,028	1,318
Loss before provision for income taxes	$ (212,183)	$ (181,894)	$ (78,270)

Income Taxes - Components of Pr

Income Taxes - Components of Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Current:
State	$ 210	$ 56	$ 37
Foreign	2,198	1,073	162
Total	2,408	1,129	199
Deferred:
Foreign	(839)	208	92
Total provision for income taxes	$ 1,569	$ 1,337	$ 291

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of the Federal Statutory Income Tax Rate and Effective Income Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Income Tax Disclosure [Abstract]
Tax at federal statutory rate	$ (72,142)	$ (61,844)	$ (26,611)
State tax, net of federal benefit	152	44	32
Stock-based compensation expense	10,866	5,328	1,570
Research and development tax credits	(3,832)	(1,999)	(1,036)
Foreign rate differential	7,106	(429)	(194)
Change in valuation allowance	58,979	60,042	26,152
Other	440	195	378
Total provision for income taxes	$ 1,569	$ 1,337	$ 291

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Deferred tax assets:
Net operating loss carryforwards	$ 137,456	$ 101,815
Tax credit carryover	12,406	6,136
Accruals and reserves	1,921	729
Deferred revenue	20,314	3,538
Stock-based compensation expense	12,588	4,258
Depreciation and amortization	3,397	2,054
Charitable contribution carryforwards	4,380	0
Total deferred tax assets	192,462	118,530
Deferred tax liabilities:
Deferred commissions	(11,000)	(5,924)
Total deferred tax liabilities	(11,000)	(5,924)
Valuation allowance	(180,926)	(112,906)
Net deferred tax (liabilities), net of valuation allowance		$ (300)
Net deferred tax assets, net of valuation allowance	$ 536

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Income Tax [Line Items]
Deferred tax assets, increase in valuation allowance	$ 68,000,000	$ 66,600,000	$ 28,800,000
Gross unrecognized tax benefit	15,470,000	$ 13,874,000	$ 4,676,000	$ 479,000
Current or cumulative interest and penalties related to uncertain tax positions	0
Federal
Income Tax [Line Items]
Net operating loss carryforwards	392,400,000
Net operating loss carryforwards, excess tax benefits from stock-based compensation	27,700,000
Research and development tax credit carryforwards	$ 10,000,000
Expiration of federal tax credit carryforwards, beginning	2,028
State
Income Tax [Line Items]
Net operating loss carryforwards	$ 402,200,000
Net operating loss carryforwards, excess tax benefits from stock-based compensation	30,200,000
Research and development tax credit carryforwards	$ 9,900,000
Tax credit carryforwards expiration, description	state research and development tax credit carryforwards have no expiration date.
Federal And State Jurisdiction
Income Tax [Line Items]
Expiration of federal and state net operating loss carryforwards, beginning	2,028
Non-U.S.
Income Tax [Line Items]
Undistributed earnings of foreign subsidiaries	$ 7,300,000

Income Taxes - Activity Related

Income Taxes - Activity Related to Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Income Tax Disclosure [Abstract]
Gross unrecognized tax benefits—beginning balance	$ 13,874	$ 4,676	$ 479
Decreases related to tax positions taken during prior years	(3,969)	0	(10)
Increases related to tax positions taken during prior years	35	0	0
Increases related to tax positions taken during current year	5,530	9,198	4,207
Gross unrecognized tax benefits—ending balance	$ 15,470	$ 13,874	$ 4,676

Segment Information - Additiona

Segment Information - Additional Information (Details)	12 Months Ended
	Jan. 31, 2016Segment
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	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 440,333	$ 174,451	$ 42,733
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	343,625	134,920	32,301
Rest of the world
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 96,708	$ 39,531	$ 10,432

Segment Information - Schedul64

Segment Information - Schedule of Long-Lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Revenues From External Customers And Long Lived Assets [Line Items]
Property and equipment, net	$ 52,629	$ 39,859
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Property and equipment, net	50,501	39,069
Rest of the world
Revenues From External Customers And Long Lived Assets [Line Items]
Property and equipment, net	$ 2,128	$ 790

401 (k) Plan - Additional Infor

401 (k) Plan - Additional Information (Details)	12 Months Ended
	Jan. 31, 2016
Compensation Related Costs [Abstract]
Maximum annual contributions per employee	100.00%

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - Certain Members of the Board of Directors that are Executive Officers of Customers - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Related Party Transaction [Line Items]
Revenue from sales transactions	$ 6,200	$ 2,100	$ 165
Purchase of product and related services	$ 728	$ 420