Nimble Storage (NMBL) 10-K 31 Mar 16 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) shares in Millions, $ in Billions	12 Months Ended
	Jan. 31, 2016	Mar. 15, 2016	Jul. 31, 2015
Document And Entity Information [Abstract]
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	NMBL
Entity Registrant Name	Nimble Storage Inc
Entity Central Index Key	1,452,751
Current Fiscal Year End Date	--01-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		84.1
Entity Public Float			$ 1.2

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Current assets:
Cash and cash equivalents	$ 211,160	$ 208,394
Restricted cash, Current	793	0
Accounts receivable, net of allowance for doubtful accounts of $25 and $0 as of January 31, 2016 and 2015, respectively	50,432	35,271
Inventories	15,994	11,981
Prepaid expenses and other current assets	5,212	4,974
Total current assets	283,591	260,620
Property and equipment, net	47,404	36,716
Restricted cash, non-current	74	3,983
Other long-term assets	680	255
Total assets	331,749	301,574
Current liabilities:
Accounts payable	24,330	19,799
Accrued compensation and benefits	19,325	21,128
Deferred revenue, current portion	54,580	34,246
Other current liabilities	8,933	8,063
Total current liabilities	107,168	83,236
Deferred revenue, non-current portion	60,265	40,200
Other long-term liabilities	8,708	9,566
Total liabilities	$ 176,141	$ 133,002
Commitments and contingencies (Note 6)
Stockholders' equity:
Preferred stock, par value of $0.001 per share; 5,000 shares authorized, no shares issued and outstanding as of January 31, 2016 and 2015	$ 0	$ 0
Common stock, par value of $0.001 per share; 750,000 shares authorized as of January 31, 2016 and 2015, respectively; 82,120 and 76,191 shares issued and outstanding as of January 31, 2016 and 2015, respectively	75	71
Additional paid-in capital	476,271	368,689
Accumulated other comprehensive loss	(731)	(250)
Accumulated deficit	(320,007)	(199,938)
Total stockholders' equity	155,608	168,572
Total liabilities and stockholders' equity	$ 331,749	$ 301,574

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 25	$ 0
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	82,120,000	76,191,000
Common stock, shares outstanding	82,120,000	76,191,000

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	$ 265,602	$ 198,129	$ 112,812
Support and service	56,613	29,544	12,921
Total revenue	322,215	227,673	125,733
Cost of revenue:
Product	86,506	62,780	36,231
Support and service	26,129	16,173	7,980
Total cost of revenue	112,635	78,953	44,211
Gross profit	209,580	148,720	81,522
Operating expenses:
Research and development	93,990	70,338	35,247
Sales and marketing	197,979	143,575	75,107
General and administrative	36,247	30,884	13,737
Total operating expenses	328,216	244,797	124,091
Loss from operations	(118,636)	(96,077)	(42,569)
Interest income, net	240	139	21
Other expense, net	(656)	(2,071)	(150)
Loss before provision for income taxes	(119,052)	(98,009)	(42,698)
Provision for income taxes	1,017	837	425
Net loss	(120,069)	(98,846)	(43,123)
Accretion of redeemable convertible preferred stock	0	0	(36)
Net loss attributable to common stockholders	$ (120,069)	$ (98,846)	$ (43,159)
Net loss per share attributable to common stockholders, basic and diluted	$ (1.52)	$ (1.37)	$ (1.61)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted	78,932	72,304	26,772

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Statement of Comprehensive Income [Abstract]
Net loss	$ (120,069)	$ (98,846)	$ (43,123)
Other comprehensive income (loss), net of taxes:
Change in cumulative translation adjustment	(481)	(275)	8
Comprehensive loss	$ (120,550)	$ (99,121)	$ (43,115)

Consolidated Statements of Rede

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Total	Initial Public Offering [Member]	Redeemable Convertible Preferred Stock [Member]	Common Stock [Member]	Common Stock [Member]Initial Public Offering [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]Initial Public Offering [Member]	Notes Receivable from Stockholders [Member]	Accumulated Other Comprehensive Income (Deficit) [Member]	Accumulated Deficit [Member]
Beginning balance at Jan. 31, 2013	$ (53,662)		$ 98,559	$ 17		$ 5,835		$ (1,562)	$ 17	$ (57,969)
Beginning balance, Shares at Jan. 31, 2013			38,868	21,388
Accretion of redeemable convertible preferred stock to redemption value	(36)		$ 36			(36)
Issuance of common stock upon initial public offering, net of issuance costs of $3,973		$ 175,702			$ 9		$ 175,693
Issuance of common stock upon initial public offering, net of issuance costs of $3,973, Shares					9,200
Conversion of preferred stock into shares of common stock	98,595		$ (98,595)	$ 39		98,556
Conversion of preferred stock into shares of common stock, Shares			(38,868)	38,868
Issuance of common stock upon exercise stock options, net of repurchases	1,486			$ 2		1,484
Issuance of common stock upon exercise stock options, net of repurchases, Shares				2,187
Repayment of notes receivable from stockholders	1,562							1,562
Vesting of early exercise of stock options	2,005					2,005
Stock-based compensation	9,149					9,149
Net loss	(43,115)								8	(43,123)
Ending balance at Jan. 31, 2014	191,686			$ 67		292,686			25	(101,092)
Ending balance, Shares at Jan. 31, 2014				71,643
Issuance costs for initial public offering	(283)					(283)
Issuance of common stock upon exercise stock options, net of repurchases	7,674			$ 3		7,671
Issuance of common stock upon exercise stock options, net of repurchases, Shares				3,508
Issuance of common stock for settlement of restricted stock units (RSUs)	0		$ 0	$ 0		0		0	0	0
Issuance of common stock for settlement of restricted stock units (RSUs), Shares				532
Shares withheld related to net share settlement of RSUs	(125)					(125)
Shares withheld related to net share settlement of RSUs, Shares				(3)
Issuance of common stock under employee stock purchase plan	9,227			$ 1		9,226
Issuance of common stock under employee stock purchase plan, Shares				511
Vesting of early exercise of stock options	2,340					2,340
Tax benefit from employee stock plans	163					163
Stock-based compensation	57,011					57,011
Net loss	(99,121)								(275)	(98,846)
Ending balance at Jan. 31, 2015	168,572			$ 71		368,689			(250)	(199,938)
Ending balance, Shares at Jan. 31, 2015				76,191
Issuance of common stock upon exercise stock options, net of repurchases	$ 8,208			$ 3		8,205
Issuance of common stock upon exercise stock options, net of repurchases, Shares	3,270			3,241
Issuance of common stock for settlement of restricted stock units (RSUs)	$ 0		$ 0	$ 0		0		$ 0	0	0
Issuance of common stock for settlement of restricted stock units (RSUs), Shares				1,920
Issuance of common stock under employee stock purchase plan	14,321			$ 1		14,320
Issuance of common stock under employee stock purchase plan, Shares				768
Vesting of early exercise of stock options	1,265					1,265
Tax benefit from employee stock plans	550					550
Stock-based compensation	83,242					83,242
Net loss	(120,550)								(481)	(120,069)
Ending balance at Jan. 31, 2016	$ 155,608			$ 75		$ 476,271			$ (731)	$ (320,007)
Ending balance, Shares at Jan. 31, 2016				82,120

Consolidated Statements of Red7

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) $ in Thousands	12 Months Ended
	Jan. 31, 2014USD ($)
Initial Public Offering [Member]
Issuance costs	$ 3,973

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	$ (120,069)	$ (98,846)	$ (43,123)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation	15,598	8,753	4,177
Stock-based compensation expense	83,304	57,067	9,149
Loss on disposal of property and equipment	182	0	148
Provision (recoveries) for allowance for doubtful accounts	25	(32)	104
Allowance for inventory reserves	157	(101)	252
Changes in operating assets and liabilities:
Accounts receivable	(15,186)	(17,563)	(4,055)
Inventories	(3,930)	(6,158)	(1,305)
Prepaid expenses and other assets	(663)	(1,841)	(2,182)
Short term restricted cash	(793)	0	0
Accounts payable	7,661	8,451	333
Deferred revenue	40,399	40,937	22,613
Accrued and other liabilities	(930)	14,709	7,147
Net cash provided by (used in) operating activities	5,755	5,376	(6,742)
Cash flows from investing activities:
Purchase of property and equipment	(29,423)	(20,820)	(13,613)
Proceeds from sale of property and equipment	0	0	27
Change in restricted cash	3,909	(83)	(3,900)
Net cash used in investing activities	(25,514)	(20,903)	(17,486)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs	0	(1,310)	176,729
Proceeds from exercise of stock options, net of repurchases	8,146	7,729	5,201
Proceeds from issuance of stock under employee stock purchase plan	14,321	9,227	0
Excess tax benefit from employee stock plans	551	163	0
Proceeds from repayment of loans from stockholders	0	0	1,571
Payment of taxes related to net settlement of restricted stock units	0	(125)	0
Net cash provided by financing activities	23,018	15,684	183,501
Foreign exchange impact on cash and cash equivalents	(493)	(249)	8
Net increase (decrease) in cash and cash equivalents	2,766	(92)	159,281
Cash and cash equivalents, beginning of period	208,394	208,486	49,205
Cash and cash equivalents, end of period	211,160	208,394	208,486
Supplemental disclosure of cash flow information:
Cash paid for income taxes	594	394	37
Cash paid for interest	105	23	0
Supplemental disclosure of noncash investing and financing activities:
Purchase of property and equipment not yet paid	3,505	6,279	1,608
Vesting of early exercised stock options	$ 1,265	$ 2,340	$ 2,005

Description of Business and Bas

Description of Business and Basis of Presentation	12 Months Ended
	Jan. 31, 2016
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Description of Business Nimble Storage, Inc., or the Company was incorporated in the state of Delaware in November 2007. The Company’s enduring mission is to engineer and deliver the industry’s most efficient flash storage platform. The Company’s Predictive Flash platform is comprised of a Unified Flash Fabric that provides a single consolidation architecture with common data services across a portfolio of All Flash and Adaptive Flash arrays and InfoSight predictive analytics with integrated support and service offerings. The Company is headquartered in San Jose, California, with employees in several international locations, including the United Kingdom, Australia, Canada, Germany, and Singapore. Basis of Presentation and Consolidation The consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles, or U.S. GAAP, and include the consolidated accounts of the Company and its subsidiaries. Intercompany accounts and transactions have been eliminated in consolidation.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Jan. 31, 2016
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies 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 in the financial statements and accompanying notes. Such estimates include, but are not limited to, the determination of the best estimated selling prices of deliverables included in multiple-deliverable revenue arrangements; the allowance for doubtful accounts; provision for excess or obsolete inventory; the useful lives of property and equipment; and the determination of the best estimated achievement of financial performance metrics related to the Company’s performance based stock awards. Actual results could differ from these estimates. Concentrations The Company’s financial instruments that are exposed to concentrations of credit risk are primarily cash and cash equivalents and trade accounts receivable. Cash and cash equivalents are maintained primarily at one financial institution, and deposits may exceed the amount of insurance provided on such deposits. Risks associated with cash and cash equivalents are mitigated by banking with a creditworthy institution. The Company has not experienced any losses on its deposits of cash and cash equivalents. The Company performs ongoing credit evaluations of its end-customers’ financial condition whenever deemed necessary and generally does not require collateral. The Company’s policy is to maintain an allowance for doubtful accounts based upon the expected collectability of its accounts receivable, which takes into consideration specific end-customer creditworthiness and current economic trends. During the third and fourth quarters of the year ended January 31, 2014, the Company consolidated the majority of its North American sales to three distributors, and as a result, accounts receivable and revenue increased in concentration. The majority of previous value added resellers, or VARs, are now purchasing from the Company’s distributors. Of all the Company’s customers, which include direct end-customers, VARs and distributors, the following distributors individually accounted for more than 10% of the Company’s accounts receivable and revenue at the end of and for each period presented: % of Accounts Receivable % of Revenue As of January 31, Year Ended January 31, 2016 2015 2016 2015 2014 Customer A 41 % 44 % 41 % 48 % 16 % Customer B 26 % 18 % 22 % * * Customer C * 16 % 16 % 21 % * * Represents less than 10%. There are no concentrations of business transacted with a particular market that would severely impact the Company’s business in the near term. However, the Company currently relies on one key contract manufacturer and supplier to produce most of its products; any disruption or termination of these arrangements could materially adversely affect the Company’s operating results. Foreign Currency Translation and Transactions The functional currency of each of the Company’s foreign subsidiaries is its respective local currency. The Company translates all monetary assets and liabilities denominated in foreign currencies into U.S. dollars using the exchange rates in effect at the balance sheet dates and other assets and liabilities using historical exchange rates. Revenue and expenses are translated at average exchange rates in effect during the year. Translation adjustments are recorded within accumulated other comprehensive income (loss), a separate component of stockholders’ equity. Foreign currency denominated transactions are initially recorded and re-measured at the end of each period using the applicable exchange rate in effect. Foreign currency re-measurement losses are recognized in other expense, net, in the consolidated statements of operations. Foreign currency re-measurement net losses recognized were $0.7 million, $2.1 million, and $0.1 million for the years ended January 31, 2016, 2015, and 2014, respectively. For the year ended January 31, 2016 and 2015, the $0.7 million and $2.1 million net losses from foreign currency remeasurement included $0.2 million and $0.7 million gains related to foreign currency forward contracts, respectively. Fair Value The carrying value of the Company’s financial instruments, including cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities, approximates fair value. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of 90 days or less at the date of purchase to be cash equivalents. Cash and cash equivalents consist principally of cash accounts and investments in money market accounts. Restricted Cash Beginning January 2016, the Company was required to maintain a monthly balance of $0.8 million for its employee medical and dental self-funded reimbursement plan. This restricted cash balance has been excluded from the Company’s cash and cash equivalents balance and is classified as restricted cash, current on the Company’s consolidated balance sheets. As of January 31, 2016, the amount of restricted cash, current was $0.8 million. As a condition of the Company’s headquarters facility lease agreement, the Company was required to maintain a letter of credit of $3.9 million, with the landlord named as the beneficiary. In January 2016, the Company cancelled the letter of credit and instead substituted the letter of credit through a line of credit obtained from Wells Fargo. As a consequence, the restricted cash was released. Accounts Receivable Accounts receivable are recorded at the invoiced amounts and do not bear interest. The Company maintains an allowance for doubtful accounts for estimated losses inherent in its accounts receivable portfolio. An allowance for doubtful accounts is calculated based on the aging of the Company’s trade receivables, historical experience, and management judgment. The Company writes off trade receivables against the allowance when management determines a balance is uncollectible and no longer actively pursues collection of the receivable. As of January 31, 2016 and 2015, the allowance for doubtful accounts was $25,000 and $0, respectively. Inventories Inventories consist primarily of raw materials related to component parts, finished goods, which include both inventory held for sale and service inventory held at service depots in support of end-customer service agreements, and end-customer evaluation inventory. Service inventory held at service depots was $5.6 million and $4.1 million as of January 31, 2016 and 2015, respectively. The following is a summary of the Company’s inventories, net of inventory provisions recorded to adjust inventory to its estimated realizable value, by major category (in thousands): As of January 31, 2016 2015 Raw materials $ 2,296 $ 2,383 Finished goods 9,005 6,871 Evaluation inventory 4,693 2,727 $ 15,994 $ 11,981 Inventory values are stated at the lower of cost (on a first-in, first-out method), or market value. A provision is recorded to adjust inventory to its estimated realizable value when inventory is determined to be in excess of anticipated demand or obsolete. In determining the provision, the Company also considers estimated recovery rates based on the nature of the inventory. Inventory write-downs are charged to the provision for inventory, which is a component of the Company’s cost of revenue. At the point of the loss recognition, a new, lower cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established cost basis. In addition, inventory reserves, which consist of mainly reserves for service inventory, were $4.5 million and $2.3 million as of January 31, 2016 and 2015, respectively. Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. Demonstration units are not sold and are transferred from inventory at cost. Depreciation is computed using the straight-line method over the following estimated useful lives: Property and Equipment Useful Life Computer equipment, lab equipment, software and Storage on Demand equipment 3 years Furniture and fixtures 5 years Leasehold improvements Shorter of estimated useful life or remaining lease term Demonstration equipment 2 years Repairs and maintenance are expensed as incurred. The Company capitalizes eligible costs to acquire or develop internal-use software that are incurred subsequent to the preliminary project stage. Capitalized costs related to internal-use software are amortized using the straight-line method over the estimated useful lives of the assets, which is generally three years. Impairment of Long-Lived Assets The Company evaluates events and changes in circumstances that could indicate carrying amounts of long-lived assets, including property and equipment, may not be recoverable. When such events or changes in circumstances occur, the Company assesses the recoverability of long-lived assets by determining whether or not the carrying value of such assets will be recovered through undiscounted expected future cash flows. If the total of the future undiscounted cash flows is less than the carrying amount of an asset, the Company records an impairment charge for the amount by which the carrying amount of the assets exceeds the fair value of the asset. Warranties The Company provides a standard one-year warranty for hardware components covering material defects in materials and workmanship. In addition, the Company provides a 90-day warranty on the embedded software in its products for non-conformance with documented specifications. The Company accrues for estimated warranty costs based upon historical experience, and periodically assesses the adequacy of its recorded warranty liability at the end of each period. These costs are expensed as incurred and included in cost of product revenue in the Company’s consolidated statements of operations. In addition, failed parts recovered from end-customers are submitted to the Company’s suppliers for repair or replacement. These cost recoveries are offset against the Company’s warranty costs. The Company records warranty liability in other current liabilities in its consolidated balance sheet. As of January 31, 2016, the Company’s warranty liability was not material. Revenue Recognition The Company generates revenue from sales of software-enabled storage products and related support. The Company’s software that is integrated on the storage products is more than incidental, and functions together with the storage product to deliver its essential functionality. The Company also offers an optional support plan (typically one to five years). The support plan includes automated support (Proactive Wellness), bug fixes, updates and upgrades to product firmware and the Company’s management platform, including InfoSight, telephone support and expedited delivery times for replacement hardware parts. While support is not contractually mandatory, substantially all products shipped have been purchased together with a support plan. The Company also periodically sells optional installation services with its products that are not essential to the functionality of the storage product. Substantially all of the Company’s end-customer arrangements contain multiple deliverables. As a result, the Company accounts for the revenue for these sales in accordance with Accounting Standards Codification (ASC) 605-25 Revenue Recognition—Multiple Element Arrangements. Arrangements are divided into separate units of accounting based on whether the delivered items have stand-alone value. In its typical end-customer arrangements, the Company considers the following to be separate units of accounting: the storage product (together with the integrated software), support services and installation services. The Company has determined that each unit of accounting has stand-alone value because they are sold separately by the Company or could be resold by an end-customer on a stand-alone basis. The Company allocates the total consideration to all deliverables based on its determination of the units of accounting and their relative selling prices. As the Company has not yet established vendor-specific objective evidence, or VSOE, or identified third-party evidence of fair value for its storage product (together with the integrated software) and installation services, it uses the best estimate of the selling price, or BESP, of each deliverable to allocate the total arrangement fee among the separate units of accounting. The Company’s process to determine its BESP for its products and installation services is based on qualitative and quantitative considerations of multiple factors, which primarily include historical stand-alone sales, margin objectives, and discount behavior. Additional considerations are given to factors such as end-customer demographics, competitive alternatives, anticipated sales volume, costs to manufacture products or provide services, pricing practices, and market conditions. The Company has established VSOE of fair value for support services based on stand-alone renewals offered to its end-customers, and allocates the fair value of consideration related to support services based on VSOE of fair value for its support services. Revenue is recognized when all of the following criteria are met: • Persuasive Evidence of an Arrangement Exists • Delivery Has Occurred • The Fee Is Fixed or Determinable • Collectability Is Reasonably Assured It is the Company’s practice to identify an end-customer from its distributors prior to shipment. In the majority of instances, products are shipped directly to the end-customers. For certain end-customer orders, products are shipped to resellers, distributors and third-party systems integrators for various reasons including importing of products to non-U.S. countries and systems integration (e.g. SmartStack integrations) prior to shipment to the end-customer or the end-customer specified location. Assuming all other revenue recognition criteria have been met, the Company generally recognizes revenue upon shipment from its origin location in California, as title and risk of loss are transferred at that time. For certain distributors, title and risk of loss is transferred upon delivery to the end-customer and revenue is recognized after delivery has been completed. The Company’s arrangements with distributors do not contain rights of return, subsequent price discounts, price protection or other allowances for shipments completed. The majority of the Company’s deferred revenue consists of the unrecognized portion of revenue from sales of its support and service contracts. The Company records amounts to be recognized during the twelve months following the balance sheet date in deferred revenue, current portion in the consolidated balance sheets, and the remainder in deferred revenue, non-current portion in the consolidated balance sheets. As of January 31, 2016, the weighted average remaining contract period related to non-current deferred revenue was approximately 2.2 years. In November 2014, the Company announced its Storage on Demand, or SoD, service offering, for enterprises and service providers managing storage in cloud environments. Under this pay-as-you-go subscription model, end-customers are generally billed on a monthly basis based on the amount of data consumed during the month. The SoD service offering includes all support services such as InfoSight. Revenue is recognized as services are performed. SoD revenue is recognized in support and service revenue in the consolidated statements of operations. Shipping Costs Shipping charges billed to end-customers are included in product revenue and the related shipping and handling costs are included in cost of revenue. Research and Development Research and development expense consists of personnel costs, including stock-based compensation expense, for the Company’s research and development personnel and product development costs, including engineering services, development software and hardware tools, depreciation of capital equipment and facility costs. Research and development costs are expensed as incurred. Advertising Costs Advertising costs are expensed as incurred and are included in sales and marketing expense. Advertising costs for the years ended January 31, 2016, 2015 and 2014 were $6.6 million, $3.0 million and $1.2 million, respectively. Stock-Based Compensation The Company determines the fair value of its stock options and shares of common stock to be issued related to its 2013 Employee Stock Purchase Plan, or the ESPP, on the date of grant utilizing the Black-Scholes-Merton option-pricing model, and is impacted by the fair value of its common stock, as well as changes in assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, the expected common stock price volatility over the term of the option awards, the expected term of the awards, risk-free interest rates and expected dividend yield. The Company generally recognizes compensation expense for stock option grants and ESPP on a straight-line basis over the requisite service period, which is generally four years for stock options, and six months to two years for ESPP. Stock-based compensation expense recognized at fair value includes the impact of estimated forfeitures. Stock-based compensation cost for restricted stock units, or RSUs, is measured based on the fair value of the underlying shares on the date of grant. The RSUs generally vest over the requisite service period. The fair value of RSUs is determined by the estimated fair value of the Company’s common stock at the time of grant. Stock-based compensation expense is recognized at fair value and includes the impact of estimated forfeitures. Income Taxes The Company accounts for income taxes under the asset and liability method. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using the enacted tax rates in effect for the years in which the temporary differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized. Derivative Financial Instruments During the year ended January 31, 2015, the Company entered into foreign currency forward contracts to minimize the short-term impact of foreign currency exchange rate fluctuations on cash and certain trade and inter-company receivables and payables. These contracts reduce the exposure to fluctuations in foreign currency exchange rate movements as the gains and losses associated with foreign currency balances are offset with the gains and losses on the forward contracts. The Company does not enter into foreign currency forward contracts for trading or speculative purposes. These instruments are marked to market through earnings every period and generally are one month in original maturity. The net gains or losses from the settlement of these foreign currency forward contracts are recorded in other expense, net in the consolidated statements of operations. Net Loss Per Share Attributable to Common Stockholders Prior to the Company’s initial public offering on December 13, 2013, the Company calculated its basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method required for companies with participating securities. The Company considers all series of its redeemable convertible preferred stock to be participating securities. In the event a dividend is declared or paid on the Company’s common stock, holders of redeemable convertible preferred stock are entitled to a proportionate share of such dividend in proportion to the holders of common stock on an as-if converted basis. Under the two-class method, basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, less shares subject to repurchase. Net loss attributable to common stockholders is determined by allocating undistributed earnings between common and redeemable convertible preferred stockholders. 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, redeemable convertible preferred stock, options to purchase common stock, repurchasable shares from early exercised options, unvested RSUs and shares subject to ESPP withholding are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive. Under the two-class method, the net loss attributable to common stockholders is not allocated to the convertible redeemable preferred stock as the convertible redeemable preferred stock do not have a contractual obligation to share in the Company’s losses. On December 13, 2013, all shares of redeemable convertible preferred stocks were converted to common stock. The following table sets forth the computation of net loss per share (in thousands, except per share amounts): Year Ended January 31, 2016 2015 2014 Numerator: Net loss $ (120,069 ) $ (98,846 ) $ (43,123 ) Add: accretion of redeemable convertible preferred stock — — (36 ) Net loss attributable to common stockholders $ (120,069 ) $ (98,846 ) $ (43,159 ) Denominator: Weighted-average number of shares outstanding—basic and diluted 78,932 72,304 26,772 Net loss per share—basic and diluted $ (1.52 ) $ (1.37 ) $ (1.61 ) The following potentially dilutive securities were excluded (as common stock equivalents) from the computation of diluted net loss per share for the periods presented as their effect would have been antidilutive (in thousands): As of January 31, 2016 2015 2014 Unvested restricted stock units 9,902 5,743 626 Shares subject to options to purchase common stock 8,593 12,360 16,329 Employee stock purchase plan 1,205 320 — Unvested early exercised common shares 184 704 1,593 Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board, or FASB, released an Accounting Standard Update, or ASU, that requires the recognition of lease assets and lease liabilities by lessees for operating leases. The standard will be effective for the Company for its first quarter of fiscal 2020, and early adoption is permitted. The Company is currently evaluating adoption methods and whether this standard will have a material impact on its consolidated financial statements and related disclosures. In November 2015, the FASB released an ASU, Balance Sheet Classification of Deferred Taxes In July 2015, the FASB issued amendments to simplify the measurement of inventory. Under the amendments, inventory will be measured at the “lower of cost and net realizable value” and options that currently exist for “market value” will be eliminated. The guidance defines net realizable value as the “estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation”. No other changes were made to the current guidance on inventory measurement. The amendments are effective for the Company for its first quarter of fiscal 2018, although early adoption is permitted. The Company is currently evaluating the effect of the updated standard on its consolidated financial statements and related disclosures. In April 2015, the FASB released an ASU on fees paid in a cloud computing arrangement. The standard requires customers in a cloud computing arrangement to evaluate whether the arrangement includes a software license. If the arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If the arrangement does not include a software license, the customer should account for the arrangement as a service contract. The standard will be effective for the Company for its first quarter of fiscal 2017, and will be applied on either a prospective or retrospective basis. The Company is currently evaluating adoption methods, but does not anticipate this standard will have a material impact on its consolidated financial statements and related disclosures. In May 2014, the FASB released an ASU, Revenue from Contracts with Customers Revenue Recognition

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Jan. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The standard describes a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, to measure the fair value: • Level 1—Inputs are unadjusted quoted prices in active markets for identical assets or liabilities. • Level 2—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. • Level 3—Inputs are unobservable inputs based on the Company’s own assumptions used to measure assets and liabilities at fair value. The inputs require significant management judgment or estimation. Beginning November 2014, the Company entered into foreign currency forward contracts to minimize the short-term impact of foreign currency exchange rate fluctuations on cash and certain trade and inter-company receivables and payables. These are not designated hedge instruments. These instruments are marked to market through earnings every period and generally have an original maturity period of one month. These instruments are classified within level 2 of the fair value hierarchy. The Company’s derivative assets and derivative liabilities as of January 31, 2016 and 2015 are as follows (in thousands): As of January 31, 2016 As of January 31, 2015 Nominal Amount Fair Value Nominal Amount Fair Value Forward Contracts: Purchased $ — $ — $ — $ — Sold $ 14,535 $ 58 $ 17,324 $ (59 )

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Jan. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	4. Balance Sheet Components Property and Equipment Property and equipment, net consisted of the following (in thousands): As of January 31, 2016 2015 Computer equipment $ 14,012 $ 9,226 Lab equipment 28,734 17,768 Software 5,470 3,443 Furniture and fixtures 4,497 3,287 Leasehold improvements 17,514 14,461 Construction in progress 3,692 1,223 Demonstration equipment 2,287 1,256 Total property and equipment 76,206 50,664 Less: accumulated depreciation (28,802 ) (13,948 ) Total property and equipment, net $ 47,404 $ 36,716 Depreciation expense related to property and equipment for the years ended January 31, 2016, 2015 and 2014 was $15.6 million, $8.8 million and $4.2 million, respectively.

Employee Loans

Employee Loans	12 Months Ended
	Jan. 31, 2016
Postemployment Benefits [Abstract]
Employee Loans	5. Employee Loans During the years ended January 31, 2011 and 2012, the Company issued full recourse loans to two employees to facilitate the exercise of their stock options. The first of these loans was issued in December 2011 with a principal amount of $1.0 million and an interest rate of at 1.3% per annum. The loan was contractually due and payable in full in December 2020 or upon such earlier date that the Company files a registration statement related to an initial public offering. The second of these loans was issued in June 2012 with a principal amount of $0.4 million and an interest of 2.3% per annum. The loan was contractually due and payable in full in June 2020 or upon such earlier date that the Company files a registration statement related to an initial public offering. The principal loan amount and the accrued interest were $1.6 million as of January 31, 2013, and were reported as a deduction from stockholders’ equity (deficit) on the Company’s consolidated statements of redeemable convertible preferred stock and stockholders’ equity (deficit). Both of these loans and related interest were repaid in full in August 2013.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Jan. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Leases The Company leases its facilities under various noncancelable operating leases with fixed rental payments. Rent expense totaled $6.2 million, $5.3 million and $3.1 million for the years ended January 31, 2016, 2015 and 2014, respectively. Future minimum commitments under these operating leases as of January 31, 2016 were as follows (in thousands): Years ending January 31: 2017 $ 7,732 2018 7,203 2019 6,985 2020 6,940 2021 7,110 Thereafter 6,506 $ 42,476 In July 2014, the Company entered into a facility lease agreement for its North Carolina office. The 84-month lease commenced on August 1, 2014. Total rent, including common area maintenance expense and fixed operating expense, payable over the lease period is $5.0 million. As part of the lease agreement, the Company received $1.4 million in tenant improvements allowance during the year ended January 31, 2016. This allowance was included in the calculation of rent expense and related deferred rent balances. In December 2014, the Company amended the lease agreement for its North Carolina office giving the Company access to an additional space on February 1, 2016 through the same term as the original facility lease. As part of the lease amendment, the Company will receive an allowance of $1.0 million for tenant improvements. In April 2013, the Company entered into a facility lease agreement for its headquarters in San Jose, California. The 96-month lease commenced on November 1, 2013. Total rent, including operating expenses, payable over the lease period is $35.5 million. As part of the lease agreement, the Company received $4.9 million in tenant improvement allowance during the year ended January 31, 2014. This allowance was included in the calculation of rent expense and related deferred rent balances. As a condition of the lease agreement, the Company is required to maintain a letter of credit of $3.9 million, with the landlord named as the beneficiary. The Company has the option to extend the term of the lease for an additional period of 60 months. Contingencies From time to time, the Company is party to litigation and subject to claims that arise in the ordinary course of business, including actions with respect to employment claims and other matters. Although the results of litigation and claims are inherently unpredictable, the Company believes that the final outcome of such matters will not have a material adverse effect on the business, consolidated financial position, results of operations or cash flows. On December 17, 2015, a purported securities class action entitled Vikramkumar v. Nimble Storage, Inc., et al. was filed in the United States District Court for the Northern District of California, against the Company and certain of its officers and directors. A second purported securities class action entitled Guardino v. Nimble Storage, Inc., et al. was filed on December 23, 2015, and a third purported class action entitled Madhani v. Nimble Storage, Inc., et al. was filed on February 5, 2016, also in the Northern District of California against the same parties. The complaints in the three actions allege claims under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended, based on allegedly misleading statements regarding the Company’s business and financial results. On March 28, 2016, the Court ordered that the three actions be consolidated under the caption In re Nimble Storage, Inc. Securities Litigation On February 23, 2016, a purported shareholder derivative action entitled Schwartz v. Vasudevan, et al. was filed in the United States District Court for the Northern District of California, against certain of the Company’s officers and directors. The complaint alleges that defendants breached their fiduciary duties by allowing the Company to make allegedly misleading statements regarding the Company’s business and financial results, and by selling stock while in possession of material non-public information. Given the early stage in the litigation, we are unable to estimate a possible loss or range of possible loss. Indemnification Some of the Company’s sales contracts require the Company to indemnify its end-customers against third-party claims asserting infringement of certain intellectual property rights, which may include patents, copyrights, trademarks, or trade secrets, and to pay judgments entered on such claims. The Company’s exposure under these indemnification provisions is generally limited to the total amount paid by the end-customer under the contract. However, certain contracts include indemnification provisions that could potentially expose the Company to losses in excess of the amount received under the contract. In addition, the Company indemnifies its 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. Purchase Commitments The Company purchases components from a variety of suppliers and one contract manufacturer to provide manufacturing services for products. During the normal course of business, in order to manage manufacturing lead times and help ensure adequate component supply, the Company enters into agreements with its contract manufacturer and suppliers that either allow them to procure inventory based upon criteria as defined by the Company or that establish the parameters defining the requirements. These agreements generally do not include any legally binding minimum commitment obligations. As of January 31, 2016, the Company had $36.4 million in several operating commitments to fulfill inventory requirements arising from growing forecasts and several non-cancelable software license and service agreements for the internal use of software and services for vendor and customer relationship management, human resource, inventory forecasting application and communication and desktop applications.

Common Stock

Common Stock	12 Months Ended
	Jan. 31, 2016
Equity [Abstract]
Common Stock	7. Common Stock In December 2013, the Company completed its initial public offering of 9.2 million shares of its common stock at a public offering price of $21.00 per share. Net cash proceeds from the initial public offering were approximately $175.4 million. In connection with the closing of the initial public offering, all of the shares of preferred stock outstanding automatically converted into an aggregate of 38.9 million shares of common stock. On December 18, 2013, the Company filed its Restated Certificate of Incorporation in connection with the closing of its initial public offering. Following the amendment, the Company had authorized capital stock of 755.0 million shares, comprising: (i) 750.0 million shares of common stock, par value $0.001 per share and (ii) 5.0 million shares of preferred stock, par value $0.001 per share. As of January 31, 2016, there were 750.0 million shares of common stock authorized with a par value of $0.001 per share. The Company had reserved the following shares of authorized but unissued common stock (in thousands): As of Issued and outstanding stock options 8,593 Unvested restricted stock units 9,902 Equity incentive plans 6,806 Employee stock purchase plan 2,576 27,877

Equity Incentive Plans

Equity Incentive Plans	12 Months Ended
	Jan. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Plans	8. Equity Incentive Plans Plan Descriptions 2008 Equity Incentive Plan In May 2008, the Company adopted the 2008 Equity Incentive Plan, or the 2008 Plan, for the benefit of its eligible employees, consultants, and independent directors. The 2008 Plan provides for the grant of stock awards, including incentive stock options, nonqualified stock options, restricted stock, stock appreciation rights and RSUs. The Company grants stock options with an exercise price equal to the fair market value of its common stock on the date of the grant, as determined by the board of directors. The Company’s equity awards vest over a period of time as determined by the board of directors and expire no later than 10 years from the date of grant. Grants to new employees generally vest over a four-year period, at a rate of 25% one year from the date the optionee’s service period begins and 1/48 monthly thereafter. Subject to adjustment for certain changes in the Company’s capital structure, the maximum aggregate number of shares of common stock that may be issued under the 2008 Plan is 55.6 million. In December 2013, in connection with the closing of the Company’s initial public offering, the 2008 Plan was terminated and shares authorized for issuance under the 2008 Plan were cancelled (except for those shares reserved for issuance upon exercise of outstanding stock options). As of January 31, 2016, options to purchase and RSUs to convert to a total of 8.8 million shares of common stock were outstanding under the 2008 Plan pursuant to their original terms and no shares were available for future grant. 2013 Equity Incentive Plan In September 2013, the Company adopted the 2013 Equity Incentive Plan, or the 2013 Plan, which became effective on December 12, 2013 and serves as the successor to the Company’s 2008 Plan. Upon completion of the Company’s initial public offering, the Company ceased granting awards under the 2008 Plan and any remaining shares available for issuance under the 2008 Plan were added to the shares reserved under the 2013 Plan. The 2013 Plan will terminate in September 2023, unless sooner terminated by the board of directors. The 2013 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock awards, stock bonus awards, stock appreciation rights, RSUs and performance awards, all of which may be granted to eligible employees, consultants or directors. Under the terms of the 2013 Plan, awards may be granted at prices not less than 100% of the fair value of the Company’s common stock, as determined by the Company’s board of directors, on the date of grant for stock options. Options vest over a period of time as determined by the board of directors, generally a four-year period, and expire ten years from date of grant. Initially, the aggregate number of shares of the Company’s common stock that may be issued pursuant to stock awards under the 2013 Plan after the 2013 Plan became effective was 10.2 million shares, plus any reserved shares not issued or subject to outstanding grants under the 2008 Plan on the date the 2013 Plan became effective, shares that are subject to stock options or RSUs granted under the 2008 Plan that cease to be subject to such stock options or other awards by forfeiture or otherwise or are issued and later forfeited or repurchased by the Company after the date the 2013 Plan became effective, and shares that are subject to stock options or other awards under the 2008 Plan that are used to pay the exercise price of an option or withheld to satisfy the tax withholding obligations related to any award. The number of shares available for grant and issuance under the 2013 Plan will automatically increase on February 1 st st 2013 Employee Stock Purchase Plan In September 2013, the Company adopted the ESPP which became effective on December 12, 2013. The ESPP initially authorizes the issuance of 2.0 million shares of the Company’s common stock pursuant to purchase rights granted to eligible employees. The number of shares of common stock reserved for issuance will automatically increase on February 1 st st The ESPP was implemented through a series of offerings of purchase rights to eligible employees. Except for the initial offering period, each offering period is for 24 months beginning March 10 th th Eligible employees may participate through payroll deductions of 1% to 15% of their earnings. Common stock will be issued to participating employees at a price per share equal to 85% of the lesser of (i) the fair market value on the offering date, or (ii) the fair market value on the purchase date. As of January 31, 2016, the Company had 2.6 million shares reserved for future issuance. Early Exercises of Stock Options Stock options granted under the 2008 Plan provide employee option holders, if approved by the board of directors, the right to exercise unvested options in exchange for restricted common stock, which is subject to a repurchase right held by the Company at the lower of (i) the fair market value of its common stock on the date of repurchase or (ii) the original purchase price. Early exercises of options are not deemed to be substantive exercises for accounting purposes and accordingly, amounts received for early exercises are recorded as a liability. As of January 31, 2016 and 2015, there were 0.2 million and 0.7 million shares, respectively, subject to repurchase related to stock options early exercised and unvested. These amounts are reclassified to common stock and additional paid-in capital as the underlying shares vest. As of January 31, 2016 and 2015, the Company recorded a liability related to these shares subject to repurchase in the amount of $0.7 million and $2.1 million, respectively, within other long-term liabilities in its consolidated balance sheets. Fair Value of Common Stock Prior to the Company’s initial public offering, the Company’s board of directors considered numerous objective and subjective factors to determine the fair value of common stock at each grant date. These factors included, but were not limited to, (i) contemporaneous valuations of common stock performed by unrelated third-party firms; (ii) the prices for the preferred stock sold to outside investors; (iii) the rights, preferences and privileges of the preferred stock relative to the common stock; (iv) the lack of marketability of the Company’s common stock; (v) developments in the business; and (vi) the likelihood of achieving a liquidity event, such as an initial public offering or a merger or acquisition of the Company, given prevailing market conditions. The Company has used the publicly quoted price as the fair value of its common stock since its common stock became publicly traded in December 2013. Stock Options and RSUs The following is a summary of the Company’s stock option and RSU activity during the year ended January 31, 2016 (in thousands, except per-share amounts): Shares Subject to Options Outstanding RSUs Shares for Grant Shares Weighted- Outstanding Weighted- Balance as of January 31, 2015 8,549 12,360 $ 3.16 5,743 $ 30.07 Additional options and RSUs authorized for issuance 3,810 — N/A — N/A Options exercised — (3,270 ) 2.52 — N/A Options canceled 497 (497 ) 4.60 — N/A Options repurchased 29 — N/A — N/A RSUs granted (6,879 ) — N/A 6,879 19.61 RSUs vested — — N/A (1,920 ) 30.37 RSUs canceled 820 — N/A (820 ) 29.58 Balance as of January 31, 2016 6,826 8,593 $ 3.32 9,882 $ 22.70 The following table summarizes information about the Company’s stock options outstanding as of January 31, 2016 (in thousands, except per-share amounts): Shares Subject to Options Outstanding Number of Weighted- Weighted- Aggregate (years) (in thousands) Vested and expected to vest as of January 31, 2016 8,428 $ 3.27 6.48 $ 29,364 Exercisable as of January 31, 2016 8,014 2.98 6.41 29,619 The options exercisable as of January 31, 2016 included options that are exercisable prior to vesting. The intrinsic value of options vested and expected to vest and become exercisable as of January 31, 2016 was calculated based on the difference between the exercise price and the fair value of the Company’s common stock as of January 31, 2016. The intrinsic value of exercised options for the years ended January 31, 2016, 2015 and 2014 was $63.1 million, $89.1 million and $10.0 million, respectively, and was calculated based on the difference between the exercise price and the fair value of the Company’s common stock as of the exercise date. The fair value of stock options that vested in the years ended January 31, 2016, 2015 and 2014 was $8.4 million, $11.4 million and $3.9 million, respectively. Stock-Based Compensation The following table summarizes the components of stock-based compensation expense related to stock options, RSUs and ESPP (in thousands): Year Ended January 31, 2016 2015 2014 Cost of product revenue $ 1,972 $ 1,508 $ 232 Cost of support and service revenue 4,743 2,380 468 Research and development 23,259 15,137 3,049 Sales and marketing 39,648 27,752 3,674 General and administrative 13,682 10,290 1,726 Total stock-based compensation expense $ 83,304 $ 57,067 $ 9,149 The Company did not issue any stock options in the year ended January 31, 2016. The weighted-average fair value of options granted was $14.52 and $3.94 per share for the years ended January 31, 2015 and 2014, respectively. The Company started to issue RSUs in the year ended January 31, 2014. The weighted-average fair value of RSUs granted was $19.61, $31.30 and $18.92 per share for the years ended January 31, 2016, 2015 and 2014, respectively. The weighted average fair value of stock purchase rights granted was $7.04, $7.20 and $6.91 per share for the year ended January 31, 2016, 2015 and 2014, respectively. The Company issues RSUs to certain employees based on the Company meeting certain performance thresholds. The estimated probability of the number of these RSUs expected to vest is assessed for each reporting period until the total shares granted are determined. For the year ended January 31, 2016 and 2015, the Company recognized expense of $5.0 million and $7.2 million stock-based compensation related to these RSUs, respectively. The reduction of expense related to these RSUs in the year ended January 31, 2016 is due to a reduction in estimated achievement of performance thresholds for fiscal year 2016. As of January 31, 2016, there was $9.2 million of unrecognized stock-based compensation expense for stock options that will be recognized over the remaining weighted-average period of 1.6 years. As of January 31, 2016, there was $183.4 million of unrecognized stock-based compensation expense for RSUs that will be recognized over the remaining weighted-average period of 2.8 years. As of January 31, 2016, there was $1.8 million of unrecognized stock-based compensation expense for stock purchase rights that will be recognized over the remaining offering period, through September 2017. The Company accounted for the stock purchase rights under ESPP at the grant date (first day of the offering period) by valuing the four purchase periods separately. The option was valued using the Black-Scholes-Merton option-pricing model with the following assumptions: Year Ended January 31, 2016 2015 2014 Expected term (in years) 0.5 - 2.0 0.5 - 2.0 0.8 - 2.3 Volatility 29% - 35% 32% - 47% 43% - 48% Risk-free interest rate 0.1% - 0.8% 0.1% - 0.6% 0.1% - 0.4% Dividend yield 0% 0% 0% Expected Term. Expected Volatility. Since the Company does not have sufficient trading history for its common stock, the expected volatility used is based on volatility of similar entities. In evaluating similarity, the Company considered factors such as industry, stage of life cycle, size, and financial leverage. Risk-Free Interest Rate Dividend Yield The Company is required to estimate forfeitures at the time of grant and revise those estimates in subsequent periods if actual forfeitures differ from those estimates. The Company uses historical data to estimate pre-vesting option forfeitures and records stock-based compensation expense only for those awards that are expected to vest.

401(k) Plan

401(k) Plan	12 Months Ended
	Jan. 31, 2016
Compensation and Retirement Disclosure [Abstract]
401(k) Plan	9. 401(k) Plan The Company has a qualified defined contribution plan under Section 401(k) of the Internal Revenue Code covering eligible employees. Participants may make pre-tax contributions to the plan from their eligible earnings up to the statutorily prescribed annual limit on pre-tax contributions under the Internal Revenue Code. Although the plan provides for a discretionary employer matching contribution, to date the Company has not made such a contribution on behalf of employees.

Income Taxes

Income Taxes	12 Months Ended
	Jan. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	10. Income Taxes The provision for income taxes is based upon the loss before provision for income taxes as follows (in thousands): Year Ended January 31, 2016 2015 2014 U.S. operations $ (122,116 ) $ (100,136 ) $ (44,007 ) Non-U.S. operations 3,064 2,127 1,309 $ (119,052 ) $ (98,009 ) $ (42,698 ) The Company’s provision for income taxes of $1.0 million for the year ended January 31, 2016 consisted of current foreign taxes, current state taxes and deferred foreign taxes. The Company’s provision for income taxes of $0.8 million for the year ended January 31, 2015 consisted of current foreign taxes, current state taxes and deferred foreign taxes. The Company’s provision for income taxes of $0.4 million for the year ended January 31, 2014 consisted of current foreign taxes, current federal taxes, current state taxes and deferred foreign taxes. The Company’s effective tax rate differs from the U.S. federal statutory tax rate due to the following (in thousands): Year Ended January 31, 2016 2015 2014 U.S. federal taxes at statutory tax rate $ (40,478 ) $ (33,323 ) $ (14,492 ) State taxes, net of federal benefit (4,196 ) (2,743 ) (1,414 ) Nondeductible expenses 405 396 218 Nondeductible stock-based compensation 4,808 5,293 1,469 Research and development credits (3,284 ) (2,739 ) (1,609 ) Foreign operation (144 ) — — Change in valuation allowance 43,935 33,942 16,253 Other (29 ) 11 — Provision for income taxes $ 1,017 $ 837 $ 425 The significant components of net deferred tax assets were as follows (in thousands): As of January 31, 2016 2015 Deferred tax assets: Net operating losses $ 62,578 $ 42,696 Depreciation 614 352 Accruals and reserves 9,038 8,090 Deferred revenue 15,819 6,748 Stock-based compensation 14,395 9,197 Research and development tax credits 9,612 6,427 Gross deferred tax assets 112,056 73,510 Depreciation and amortization (18 ) (11 ) Net deferred tax assets prior to valuation allowance 112,038 73,499 Valuation allowance (111,380 ) (73,235 ) Total net deferred tax assets $ 658 $ 264 The net valuation allowance increased by $38.1 million during the year ended January 31, 2016. Management has recorded a full valuation allowance against its net domestic deferred tax assets as it is not more likely than not that the assets will be realized based on the Company’s history of losses. The passage of Protecting Americans from Tax Hike Act of 2015, on December 18, 2015, retroactively and permanently reinstated the U.S. federal R&D tax credit effective January 1, 2015. As of January 31, 2016, the Company had net operating loss, or NOL, carryforwards and research and development credits as follows (in thousands): Amount Expiration Year Net operating losses, federal $ 262,815 2028-2036 Net operating losses, state 188,759 2028-2036 Research and development credits, federal 9,102 2028-2036 Research and development credits, California 8,625 Indefinite Research and development credits, North Carolina 156 2029 - Indefinite The Company uses the ‘with-and-without’ approach to determine the recognition and measurement of excess tax benefits. Accordingly, the Company has elected to recognize excess income tax benefits from stock option exercises in additional paid in capital only if an incremental income tax benefit would be realized after considering all other tax attributes presently available to the Company. As of January 31, 2016, the amount of such excess tax benefits from stock options included in NOLs was $97.3 million and $22.9 million for federal and California purposes. In addition, the Company has elected to account for the indirect effects of stock-based awards on other tax attributes, such as the research and alternative minimum tax credits, through its statements of operations. Under Section 382 of the Internal Revenue Code, the Company’s ability to utilize NOL carryforwards or other tax attributes, such as research tax credits, in any taxable year may be limited if the Company experiences an “ownership change.” A Section 382 “ownership change” generally occurs if one or more stockholders or groups of stockholders who own at least 5% of the Company’s stock increase their ownership by more than 50 percentage points over their lowest ownership percentage within a rolling three-year period. Similar rules may apply under state tax laws. It is possible that an ownership change, or any future ownership change, could have a material effect on the use of the Company’s NOL carryforwards or other tax attributes. Due to the existence of the valuation allowance, future changes in unrecognized tax benefits will not impact the Company’s effective tax rate. The Company does not intend on remitting undistributed earnings of foreign subsidiaries and, accordingly, no deferred tax liability has been established relative to these earnings. As of January 31, 2016, the Company’s undistributed earnings of foreign subsidiaries were $4.6 million. The Company recognizes interest and penalties related to uncertain tax positions, if any, as a component of its income tax provision. The Company recognized de minimis interest and penalties related to uncertain tax positions for the years ended January 31, 2016, 2015 and 2014. A reconciliation of the beginning and ending balances of gross unrecognized tax benefits, before interest and penalties is as follows (in thousands): Amount Balance as of January 31, 2013 1,083 Additions for tax positions related to prior year 9 Additions for tax positions related to current year 955 Reductions for tax positions related to prior year — Balance as of January 31, 2014 2,047 Additions for tax positions related to prior year 153 Additions for tax positions related to current year 1,594 Reductions for tax positions related to prior year (6 ) Balance as of January 31, 2015 $ 3,788 Additions for tax positions related to prior year 1,491 Additions for tax positions related to current year 2,206 Reductions for tax positions related to prior year (775 ) Balance as of January 31, 2016 $ 6,710 The gross unrecognized tax benefits, if recognized, would affect the effective tax rate by approximately $410,000 and $39,000 as of January 31, 2016 and 2015, respectively. While it is often difficult to predict the final outcome of any particular uncertain tax position, the Company does not believe it is reasonably possible that the total amount of unrecognized tax benefits as of January 31, 2016 will materially change in the next 12 months. The Company files federal, state, and foreign income tax returns in many jurisdictions in the United States and abroad. For U.S. federal and state income tax purposes, the statute of limitations currently remains open for all years due to the Company’s NOL carryforwards. The Company is not currently under examination in any jurisdiction.

Segments

Segments	12 Months Ended
	Jan. 31, 2016
Segment Reporting [Abstract]
Segments	11. Segments The Company’s chief operating decision maker is its chief executive officer. The chief executive officer reviews consolidated financial information accompanied by information about revenue by product line for purposes of allocating resources and evaluating financial performance. The Company has one business activity and there are no segment managers who are held accountable for operations, or operating results for levels or components. In addition, the majority of the Company’s operations and end-customers are located in the United States. As such, the Company has a single reporting segment and a single operating unit structure. Revenue by region, based on the bill to mailing address of the end-customer, for the periods presented was as follows (in thousands): Year Ended January 31, 2016 2015 2014 North America $ 253,307 $ 186,145 $ 107,305 EMEA 46,062 28,210 11,731 APAC 22,846 13,303 6,550 Other — 15 147 Total revenue $ 322,215 $ 227,673 $ 125,733 Long-lived assets located in the following countries and regions as of each period end were as follows (in thousands): As of January 31, 2016 2015 North America $ 47,277 $ 40,521 Other 881 433 Total long-lived assets $ 48,158 $ 40,954

Line of Credit

Line of Credit	12 Months Ended
	Jan. 31, 2016
Debt Disclosure [Abstract]
Line of Credit	12. Line of Credit In October 2013, the Company entered into an agreement with Wells Fargo Bank, National Association, or Wells Fargo, to provide a secured revolving credit facility, or the Credit Facility, that allows the Company to borrow up to $15.0 million for general corporate purposes. There was a $0.9 million reduction of the available line related to a letter of credit issued in July 2014 for the Company’s facility lease in North Carolina. In April 2015, the Company increased its letter of credit from $0.9 million to $1.1 million, with the landlord named as the beneficiary. In January 2016, there was a $3.9 million reduction of the available line related to a letter of credit issued for the Company’s headquarters facility lease in California, with the landlord named as the beneficiary. As a consequence, the Company released its restricted cash of $3.9 million. As of January 31, 2016, the remaining Credit Facility available for borrowings was $10.0 million. Amounts outstanding under the Credit Facility will bear interest at Wells Fargo’s prime rate with accrued interest payable on a monthly basis. In addition, the Company is obligated to pay a commitment fee of 0.20% per annum on the unused portion of the Credit Facility, with such fee payable on a quarterly basis. As of January 31, 2016, the commitment fee was capitalized and being amortized on the Company’s consolidated balance sheet. The Credit Facility was renewed in September 2014 for an incremental two-year period and now expires in October 2016. Under the Credit Facility renewal, the Company granted to Wells Fargo a first priority lien in its accounts receivable and other corporate assets, agreed to not pledge its intellectual property to other parties and became subject to certain reporting and financial covenants, as follows: (i) maintain minimum tangible net worth, defined as the aggregate of total stockholders’ equity plus subordinated debt less any intangible assets and less any loans or advances to, or investments in, any related entities or individuals, of $135 million; and (ii) maintain a monthly ratio of not less than 1.25 to 1.00, based on the aggregate of its cash and net accounts receivable divided by total current liabilities minus current deferred revenue. As of January 31, 2016, no amounts had been drawn against the Credit Facility and the Company was in compliance with all covenants associated with the Credit Facility.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (unaudited)	12 Months Ended
	Jan. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (unaudited)	13. Selected Quarterly Financial Data (unaudited) The following tables set forth selected unaudited quarterly consolidated statements of operations data for each of the eight quarters in fiscal 2016 and 2015 (in thousands, except per share data): Quarter Ended April 30, July 31, October 31, January 31, April 30, July 31, October 31, January 31, Net revenues $ 46,547 $ 53,761 $ 59,096 $ 68,269 $ 71,288 $ 80,109 $ 80,727 $ 90,091 Gross profit 30,212 35,245 38,432 44,831 46,495 52,345 52,690 58,050 Net loss $ (19,595 ) $ (26,117 ) $ (28,389 ) $ (24,745 ) $ (28,986 ) $ (30,109 ) $ (28,574 ) $ (32,400 ) Net loss per share, basic and diluted $ (0.28 ) $ (0.37 ) $ (0.39 ) $ (0.33 ) $ (0.38 ) $ (0.38 ) $ (0.36 ) $ (0.40 )

Description of Business and B22

Description of Business and Basis of Presentation (Policies)	12 Months Ended
	Jan. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles, or U.S. GAAP, and include the consolidated accounts of the Company and its subsidiaries. Intercompany accounts and transactions have been eliminated in consolidation.
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 in the financial statements and accompanying notes. Such estimates include, but are not limited to, the determination of the best estimated selling prices of deliverables included in multiple-deliverable revenue arrangements; the allowance for doubtful accounts; provision for excess or obsolete inventory; the useful lives of property and equipment; and the determination of the best estimated achievement of financial performance metrics related to the Company’s performance based stock awards. Actual results could differ from these estimates.
Concentrations	Concentrations The Company’s financial instruments that are exposed to concentrations of credit risk are primarily cash and cash equivalents and trade accounts receivable. Cash and cash equivalents are maintained primarily at one financial institution, and deposits may exceed the amount of insurance provided on such deposits. Risks associated with cash and cash equivalents are mitigated by banking with a creditworthy institution. The Company has not experienced any losses on its deposits of cash and cash equivalents. The Company performs ongoing credit evaluations of its end-customers’ financial condition whenever deemed necessary and generally does not require collateral. The Company’s policy is to maintain an allowance for doubtful accounts based upon the expected collectability of its accounts receivable, which takes into consideration specific end-customer creditworthiness and current economic trends. During the third and fourth quarters of the year ended January 31, 2014, the Company consolidated the majority of its North American sales to three distributors, and as a result, accounts receivable and revenue increased in concentration. The majority of previous value added resellers, or VARs, are now purchasing from the Company’s distributors. Of all the Company’s customers, which include direct end-customers, VARs and distributors, the following distributors individually accounted for more than 10% of the Company’s accounts receivable and revenue at the end of and for each period presented: % of Accounts Receivable % of Revenue As of January 31, Year Ended January 31, 2016 2015 2016 2015 2014 Customer A 41 % 44 % 41 % 48 % 16 % Customer B 26 % 18 % 22 % * * Customer C * 16 % 16 % 21 % * * Represents less than 10%. There are no concentrations of business transacted with a particular market that would severely impact the Company’s business in the near term. However, the Company currently relies on one key contract manufacturer and supplier to produce most of its products; any disruption or termination of these arrangements could materially adversely affect the Company’s operating results.
Foreign Currency Translation and Transactions	Foreign Currency Translation and Transactions The functional currency of each of the Company’s foreign subsidiaries is its respective local currency. The Company translates all monetary assets and liabilities denominated in foreign currencies into U.S. dollars using the exchange rates in effect at the balance sheet dates and other assets and liabilities using historical exchange rates. Revenue and expenses are translated at average exchange rates in effect during the year. Translation adjustments are recorded within accumulated other comprehensive income (loss), a separate component of stockholders’ equity. Foreign currency denominated transactions are initially recorded and re-measured at the end of each period using the applicable exchange rate in effect. Foreign currency re-measurement losses are recognized in other expense, net, in the consolidated statements of operations. Foreign currency re-measurement net losses recognized were $0.7 million, $2.1 million, and $0.1 million for the years ended January 31, 2016, 2015, and 2014, respectively. For the year ended January 31, 2016 and 2015, the $0.7 million and $2.1 million net losses from foreign currency remeasurement included $0.2 million and $0.7 million gains related to foreign currency forward contracts, respectively.
Fair Value	Fair Value The carrying value of the Company’s financial instruments, including cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities, approximates fair value.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of 90 days or less at the date of purchase to be cash equivalents. Cash and cash equivalents consist principally of cash accounts and investments in money market accounts.
Restricted Cash	Restricted Cash Beginning January 2016, the Company was required to maintain a monthly balance of $0.8 million for its employee medical and dental self-funded reimbursement plan. This restricted cash balance has been excluded from the Company’s cash and cash equivalents balance and is classified as restricted cash, current on the Company’s consolidated balance sheets. As of January 31, 2016, the amount of restricted cash, current was $0.8 million. As a condition of the Company’s headquarters facility lease agreement, the Company was required to maintain a letter of credit of $3.9 million, with the landlord named as the beneficiary. In January 2016, the Company cancelled the letter of credit and instead substituted the letter of credit through a line of credit obtained from Wells Fargo. As a consequence, the restricted cash was released.
Accounts Receivable	Accounts Receivable Accounts receivable are recorded at the invoiced amounts and do not bear interest. The Company maintains an allowance for doubtful accounts for estimated losses inherent in its accounts receivable portfolio. An allowance for doubtful accounts is calculated based on the aging of the Company’s trade receivables, historical experience, and management judgment. The Company writes off trade receivables against the allowance when management determines a balance is uncollectible and no longer actively pursues collection of the receivable. As of January 31, 2016 and 2015, the allowance for doubtful accounts was $25,000 and $0, respectively.
Inventories	Inventories Inventories consist primarily of raw materials related to component parts, finished goods, which include both inventory held for sale and service inventory held at service depots in support of end-customer service agreements, and end-customer evaluation inventory. Service inventory held at service depots was $5.6 million and $4.1 million as of January 31, 2016 and 2015, respectively. The following is a summary of the Company’s inventories, net of inventory provisions recorded to adjust inventory to its estimated realizable value, by major category (in thousands): As of January 31, 2016 2015 Raw materials $ 2,296 $ 2,383 Finished goods 9,005 6,871 Evaluation inventory 4,693 2,727 $ 15,994 $ 11,981 Inventory values are stated at the lower of cost (on a first-in, first-out method), or market value. A provision is recorded to adjust inventory to its estimated realizable value when inventory is determined to be in excess of anticipated demand or obsolete. In determining the provision, the Company also considers estimated recovery rates based on the nature of the inventory. Inventory write-downs are charged to the provision for inventory, which is a component of the Company’s cost of revenue. At the point of the loss recognition, a new, lower cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in that newly established cost basis. In addition, inventory reserves, which consist of mainly reserves for service inventory, were $4.5 million and $2.3 million as of January 31, 2016 and 2015, respectively.
Property and Equipment	Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. Demonstration units are not sold and are transferred from inventory at cost. Depreciation is computed using the straight-line method over the following estimated useful lives: Property and Equipment Useful Life Computer equipment, lab equipment, software and Storage on Demand equipment 3 years Furniture and fixtures 5 years Leasehold improvements Shorter of estimated useful life or remaining lease term Demonstration equipment 2 years Repairs and maintenance are expensed as incurred. The Company capitalizes eligible costs to acquire or develop internal-use software that are incurred subsequent to the preliminary project stage. Capitalized costs related to internal-use software are amortized using the straight-line method over the estimated useful lives of the assets, which is generally three years.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates events and changes in circumstances that could indicate carrying amounts of long-lived assets, including property and equipment, may not be recoverable. When such events or changes in circumstances occur, the Company assesses the recoverability of long-lived assets by determining whether or not the carrying value of such assets will be recovered through undiscounted expected future cash flows. If the total of the future undiscounted cash flows is less than the carrying amount of an asset, the Company records an impairment charge for the amount by which the carrying amount of the assets exceeds the fair value of the asset.
Warranties	Warranties The Company provides a standard one-year warranty for hardware components covering material defects in materials and workmanship. In addition, the Company provides a 90-day warranty on the embedded software in its products for non-conformance with documented specifications. The Company accrues for estimated warranty costs based upon historical experience, and periodically assesses the adequacy of its recorded warranty liability at the end of each period. These costs are expensed as incurred and included in cost of product revenue in the Company’s consolidated statements of operations. In addition, failed parts recovered from end-customers are submitted to the Company’s suppliers for repair or replacement. These cost recoveries are offset against the Company’s warranty costs. The Company records warranty liability in other current liabilities in its consolidated balance sheet. As of January 31, 2016, the Company’s warranty liability was not material.
Revenue Recognition	Revenue Recognition The Company generates revenue from sales of software-enabled storage products and related support. The Company’s software that is integrated on the storage products is more than incidental, and functions together with the storage product to deliver its essential functionality. The Company also offers an optional support plan (typically one to five years). The support plan includes automated support (Proactive Wellness), bug fixes, updates and upgrades to product firmware and the Company’s management platform, including InfoSight, telephone support and expedited delivery times for replacement hardware parts. While support is not contractually mandatory, substantially all products shipped have been purchased together with a support plan. The Company also periodically sells optional installation services with its products that are not essential to the functionality of the storage product. Substantially all of the Company’s end-customer arrangements contain multiple deliverables. As a result, the Company accounts for the revenue for these sales in accordance with Accounting Standards Codification (ASC) 605-25 Revenue Recognition—Multiple Element Arrangements. Arrangements are divided into separate units of accounting based on whether the delivered items have stand-alone value. In its typical end-customer arrangements, the Company considers the following to be separate units of accounting: the storage product (together with the integrated software), support services and installation services. The Company has determined that each unit of accounting has stand-alone value because they are sold separately by the Company or could be resold by an end-customer on a stand-alone basis. The Company allocates the total consideration to all deliverables based on its determination of the units of accounting and their relative selling prices. As the Company has not yet established vendor-specific objective evidence, or VSOE, or identified third-party evidence of fair value for its storage product (together with the integrated software) and installation services, it uses the best estimate of the selling price, or BESP, of each deliverable to allocate the total arrangement fee among the separate units of accounting. The Company’s process to determine its BESP for its products and installation services is based on qualitative and quantitative considerations of multiple factors, which primarily include historical stand-alone sales, margin objectives, and discount behavior. Additional considerations are given to factors such as end-customer demographics, competitive alternatives, anticipated sales volume, costs to manufacture products or provide services, pricing practices, and market conditions. The Company has established VSOE of fair value for support services based on stand-alone renewals offered to its end-customers, and allocates the fair value of consideration related to support services based on VSOE of fair value for its support services. Revenue is recognized when all of the following criteria are met: • Persuasive Evidence of an Arrangement Exists • Delivery Has Occurred • The Fee Is Fixed or Determinable • Collectability Is Reasonably Assured It is the Company’s practice to identify an end-customer from its distributors prior to shipment. In the majority of instances, products are shipped directly to the end-customers. For certain end-customer orders, products are shipped to resellers, distributors and third-party systems integrators for various reasons including importing of products to non-U.S. countries and systems integration (e.g. SmartStack integrations) prior to shipment to the end-customer or the end-customer specified location. Assuming all other revenue recognition criteria have been met, the Company generally recognizes revenue upon shipment from its origin location in California, as title and risk of loss are transferred at that time. For certain distributors, title and risk of loss is transferred upon delivery to the end-customer and revenue is recognized after delivery has been completed. The Company’s arrangements with distributors do not contain rights of return, subsequent price discounts, price protection or other allowances for shipments completed. The majority of the Company’s deferred revenue consists of the unrecognized portion of revenue from sales of its support and service contracts. The Company records amounts to be recognized during the twelve months following the balance sheet date in deferred revenue, current portion in the consolidated balance sheets, and the remainder in deferred revenue, non-current portion in the consolidated balance sheets. As of January 31, 2016, the weighted average remaining contract period related to non-current deferred revenue was approximately 2.2 years. In November 2014, the Company announced its Storage on Demand, or SoD, service offering, for enterprises and service providers managing storage in cloud environments. Under this pay-as-you-go subscription model, end-customers are generally billed on a monthly basis based on the amount of data consumed during the month. The SoD service offering includes all support services such as InfoSight. Revenue is recognized as services are performed. SoD revenue is recognized in support and service revenue in the consolidated statements of operations.
Shipping Costs	Shipping Costs Shipping charges billed to end-customers are included in product revenue and the related shipping and handling costs are included in cost of revenue.
Research and Development	Research and Development Research and development expense consists of personnel costs, including stock-based compensation expense, for the Company’s research and development personnel and product development costs, including engineering services, development software and hardware tools, depreciation of capital equipment and facility costs. Research and development costs are expensed as incurred.
Advertising Costs	Advertising Costs Advertising costs are expensed as incurred and are included in sales and marketing expense. Advertising costs for the years ended January 31, 2016, 2015 and 2014 were $6.6 million, $3.0 million and $1.2 million, respectively.
Stock-Based Compensation	Stock-Based Compensation The Company determines the fair value of its stock options and shares of common stock to be issued related to its 2013 Employee Stock Purchase Plan, or the ESPP, on the date of grant utilizing the Black-Scholes-Merton option-pricing model, and is impacted by the fair value of its common stock, as well as changes in assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, the expected common stock price volatility over the term of the option awards, the expected term of the awards, risk-free interest rates and expected dividend yield. The Company generally recognizes compensation expense for stock option grants and ESPP on a straight-line basis over the requisite service period, which is generally four years for stock options, and six months to two years for ESPP. Stock-based compensation expense recognized at fair value includes the impact of estimated forfeitures. Stock-based compensation cost for restricted stock units, or RSUs, is measured based on the fair value of the underlying shares on the date of grant. The RSUs generally vest over the requisite service period. The fair value of RSUs is determined by the estimated fair value of the Company’s common stock at the time of grant. Stock-based compensation expense is recognized at fair value and includes the impact of estimated forfeitures.
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using the enacted tax rates in effect for the years in which the temporary differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized.
Derivative Financial Instruments	Derivative Financial Instruments During the year ended January 31, 2015, the Company entered into foreign currency forward contracts to minimize the short-term impact of foreign currency exchange rate fluctuations on cash and certain trade and inter-company receivables and payables. These contracts reduce the exposure to fluctuations in foreign currency exchange rate movements as the gains and losses associated with foreign currency balances are offset with the gains and losses on the forward contracts. The Company does not enter into foreign currency forward contracts for trading or speculative purposes. These instruments are marked to market through earnings every period and generally are one month in original maturity. The net gains or losses from the settlement of these foreign currency forward contracts are recorded in other expense, net in the consolidated statements of operations.
Net Loss Per Share Attributable to Common Stockholders	Net Loss Per Share Attributable to Common Stockholders Prior to the Company’s initial public offering on December 13, 2013, the Company calculated its basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method required for companies with participating securities. The Company considers all series of its redeemable convertible preferred stock to be participating securities. In the event a dividend is declared or paid on the Company’s common stock, holders of redeemable convertible preferred stock are entitled to a proportionate share of such dividend in proportion to the holders of common stock on an as-if converted basis. Under the two-class method, basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, less shares subject to repurchase. Net loss attributable to common stockholders is determined by allocating undistributed earnings between common and redeemable convertible preferred stockholders. 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, redeemable convertible preferred stock, options to purchase common stock, repurchasable shares from early exercised options, unvested RSUs and shares subject to ESPP withholding are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive. Under the two-class method, the net loss attributable to common stockholders is not allocated to the convertible redeemable preferred stock as the convertible redeemable preferred stock do not have a contractual obligation to share in the Company’s losses. On December 13, 2013, all shares of redeemable convertible preferred stocks were converted to common stock. The following table sets forth the computation of net loss per share (in thousands, except per share amounts): Year Ended January 31, 2016 2015 2014 Numerator: Net loss $ (120,069 ) $ (98,846 ) $ (43,123 ) Add: accretion of redeemable convertible preferred stock — — (36 ) Net loss attributable to common stockholders $ (120,069 ) $ (98,846 ) $ (43,159 ) Denominator: Weighted-average number of shares outstanding—basic and diluted 78,932 72,304 26,772 Net loss per share—basic and diluted $ (1.52 ) $ (1.37 ) $ (1.61 ) The following potentially dilutive securities were excluded (as common stock equivalents) from the computation of diluted net loss per share for the periods presented as their effect would have been antidilutive (in thousands): As of January 31, 2016 2015 2014 Unvested restricted stock units 9,902 5,743 626 Shares subject to options to purchase common stock 8,593 12,360 16,329 Employee stock purchase plan 1,205 320 — Unvested early exercised common shares 184 704 1,593
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the Financial Accounting Standards Board, or FASB, released an Accounting Standard Update, or ASU, that requires the recognition of lease assets and lease liabilities by lessees for operating leases. The standard will be effective for the Company for its first quarter of fiscal 2020, and early adoption is permitted. The Company is currently evaluating adoption methods and whether this standard will have a material impact on its consolidated financial statements and related disclosures. In November 2015, the FASB released an ASU, Balance Sheet Classification of Deferred Taxes In July 2015, the FASB issued amendments to simplify the measurement of inventory. Under the amendments, inventory will be measured at the “lower of cost and net realizable value” and options that currently exist for “market value” will be eliminated. The guidance defines net realizable value as the “estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation”. No other changes were made to the current guidance on inventory measurement. The amendments are effective for the Company for its first quarter of fiscal 2018, although early adoption is permitted. The Company is currently evaluating the effect of the updated standard on its consolidated financial statements and related disclosures. In April 2015, the FASB released an ASU on fees paid in a cloud computing arrangement. The standard requires customers in a cloud computing arrangement to evaluate whether the arrangement includes a software license. If the arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If the arrangement does not include a software license, the customer should account for the arrangement as a service contract. The standard will be effective for the Company for its first quarter of fiscal 2017, and will be applied on either a prospective or retrospective basis. The Company is currently evaluating adoption methods, but does not anticipate this standard will have a material impact on its consolidated financial statements and related disclosures. In May 2014, the FASB released an ASU, Revenue from Contracts with Customers Revenue Recognition
Fair Value Measurements	Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The standard describes a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, to measure the fair value: • Level 1—Inputs are unadjusted quoted prices in active markets for identical assets or liabilities. • Level 2—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. • Level 3—Inputs are unobservable inputs based on the Company’s own assumptions used to measure assets and liabilities at fair value. The inputs require significant management judgment or estimation.
Commitments and Contingencies	From time to time, the Company is party to litigation and subject to claims that arise in the ordinary course of business, including actions with respect to employment claims and other matters. Although the results of litigation and claims are inherently unpredictable, the Company believes that the final outcome of such matters will not have a material adverse effect on the business, consolidated financial position, results of operations or cash flows.
Segment Reporting	The Company’s chief operating decision maker is its chief executive officer. The chief executive officer reviews consolidated financial information accompanied by information about revenue by product line for purposes of allocating resources and evaluating financial performance. The Company has one business activity and there are no segment managers who are held accountable for operations, or operating results for levels or components. In addition, the majority of the Company’s operations and end-customers are located in the United States. As such, the Company has a single reporting segment and a single operating unit structure.

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Jan. 31, 2016
Accounting Policies [Abstract]
Percentage of Company's Accounts Receivable and Revenue	Of all the Company’s customers, which include direct end-customers, VARs and distributors, the following distributors individually accounted for more than 10% of the Company’s accounts receivable and revenue at the end of and for each period presented: % of Accounts Receivable % of Revenue As of January 31, Year Ended January 31, 2016 2015 2016 2015 2014 Customer A 41 % 44 % 41 % 48 % 16 % Customer B 26 % 18 % 22 % * * Customer C * 16 % 16 % 21 % * * Represents less than 10%.
Summary of Company's Inventories, Net of Inventory Provisions Recorded to Adjust Inventory to Estimated Realizable Value by Major Category	The following is a summary of the Company’s inventories, net of inventory provisions recorded to adjust inventory to its estimated realizable value, by major category (in thousands): As of January 31, 2016 2015 Raw materials $ 2,296 $ 2,383 Finished goods 9,005 6,871 Evaluation inventory 4,693 2,727 $ 15,994 $ 11,981
Estimated Useful Lives of Property and Equipment	Depreciation is computed using the straight-line method over the following estimated useful lives: Property and Equipment Useful Life Computer equipment, lab equipment, software and Storage on Demand equipment 3 years Furniture and fixtures 5 years Leasehold improvements Shorter of estimated useful life or remaining lease term Demonstration equipment 2 years
Computation of Net Loss Per Share	The following table sets forth the computation of net loss per share (in thousands, except per share amounts): Year Ended January 31, 2016 2015 2014 Numerator: Net loss $ (120,069 ) $ (98,846 ) $ (43,123 ) Add: accretion of redeemable convertible preferred stock — — (36 ) Net loss attributable to common stockholders $ (120,069 ) $ (98,846 ) $ (43,159 ) Denominator: Weighted-average number of shares outstanding—basic and diluted 78,932 72,304 26,772 Net loss per share—basic and diluted $ (1.52 ) $ (1.37 ) $ (1.61 )
Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share	The following potentially dilutive securities were excluded (as common stock equivalents) from the computation of diluted net loss per share for the periods presented as their effect would have been antidilutive (in thousands): As of January 31, 2016 2015 2014 Unvested restricted stock units 9,902 5,743 626 Shares subject to options to purchase common stock 8,593 12,360 16,329 Employee stock purchase plan 1,205 320 — Unvested early exercised common shares 184 704 1,593

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Jan. 31, 2016
Fair Value Disclosures [Abstract]
Schedule of Derivative Assets and Derivative Liabilities	The Company’s derivative assets and derivative liabilities as of January 31, 2016 and 2015 are as follows (in thousands): As of January 31, 2016 As of January 31, 2015 Nominal Amount Fair Value Nominal Amount Fair Value Forward Contracts: Purchased $ — $ — $ — $ — Sold $ 14,535 $ 58 $ 17,324 $ (59 )

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Jan. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): As of January 31, 2016 2015 Computer equipment $ 14,012 $ 9,226 Lab equipment 28,734 17,768 Software 5,470 3,443 Furniture and fixtures 4,497 3,287 Leasehold improvements 17,514 14,461 Construction in progress 3,692 1,223 Demonstration equipment 2,287 1,256 Total property and equipment 76,206 50,664 Less: accumulated depreciation (28,802 ) (13,948 ) Total property and equipment, net $ 47,404 $ 36,716

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Jan. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Commitments Under Operating Leases	Future minimum commitments under these operating leases as of January 31, 2016 were as follows (in thousands): Years ending January 31: 2017 $ 7,732 2018 7,203 2019 6,985 2020 6,940 2021 7,110 Thereafter 6,506 $ 42,476

Common Stock (Tables)

Common Stock (Tables)	12 Months Ended
	Jan. 31, 2016
Equity [Abstract]
Summary of Reserved Shares of Authorized but Unissued Common Stock	The Company had reserved the following shares of authorized but unissued common stock (in thousands): As of Issued and outstanding stock options 8,593 Unvested restricted stock units 9,902 Equity incentive plans 6,806 Employee stock purchase plan 2,576 27,877

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	12 Months Ended
	Jan. 31, 2016
Schedule of Stock Option and RSU Award Activity	The following is a summary of the Company’s stock option and RSU activity during the year ended January 31, 2016 (in thousands, except per-share amounts): Shares Subject to Options Outstanding RSUs Shares for Grant Shares Weighted- Outstanding Weighted- Balance as of January 31, 2015 8,549 12,360 $ 3.16 5,743 $ 30.07 Additional options and RSUs authorized for issuance 3,810 — N/A — N/A Options exercised — (3,270 ) 2.52 — N/A Options canceled 497 (497 ) 4.60 — N/A Options repurchased 29 — N/A — N/A RSUs granted (6,879 ) — N/A 6,879 19.61 RSUs vested — — N/A (1,920 ) 30.37 RSUs canceled 820 — N/A (820 ) 29.58 Balance as of January 31, 2016 6,826 8,593 $ 3.32 9,882 $ 22.70
Schedule of Stock Options Outstanding	The following table summarizes information about the Company’s stock options outstanding as of January 31, 2016 (in thousands, except per-share amounts): Shares Subject to Options Outstanding Number of Weighted- Weighted- Aggregate (years) (in thousands) Vested and expected to vest as of January 31, 2016 8,428 $ 3.27 6.48 $ 29,364 Exercisable as of January 31, 2016 8,014 2.98 6.41 29,619
Components of Stock-based Compensation Expense Related to Stock Options, RSUs and ESPP	The following table summarizes the components of stock-based compensation expense related to stock options, RSUs and ESPP (in thousands): Year Ended January 31, 2016 2015 2014 Cost of product revenue $ 1,972 $ 1,508 $ 232 Cost of support and service revenue 4,743 2,380 468 Research and development 23,259 15,137 3,049 Sales and marketing 39,648 27,752 3,674 General and administrative 13,682 10,290 1,726 Total stock-based compensation expense $ 83,304 $ 57,067 $ 9,149
Stock Purchase Rights [Member]
Schedule of Option Valued Using Black-Scholes-Merton Option-Pricing Model	The option was valued using the Black-Scholes-Merton option-pricing model with the following assumptions: Year Ended January 31, 2016 2015 2014 Expected term (in years) 0.5 - 2.0 0.5 - 2.0 0.8 - 2.3 Volatility 29% - 35% 32% - 47% 43% - 48% Risk-free interest rate 0.1% - 0.8% 0.1% - 0.6% 0.1% - 0.4% Dividend yield 0% 0% 0%

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Jan. 31, 2016
Income Tax Disclosure [Abstract]
Schedule of Provision for income taxes	The provision for income taxes is based upon the loss before provision for income taxes as follows (in thousands): Year Ended January 31, 2016 2015 2014 U.S. operations $ (122,116 ) $ (100,136 ) $ (44,007 ) Non-U.S. operations 3,064 2,127 1,309 $ (119,052 ) $ (98,009 ) $ (42,698 )
Schedule of Effective Tax Rate Differs from U.S. Federal Statutory Tax Rate	The Company’s effective tax rate differs from the U.S. federal statutory tax rate due to the following (in thousands): Year Ended January 31, 2016 2015 2014 U.S. federal taxes at statutory tax rate $ (40,478 ) $ (33,323 ) $ (14,492 ) State taxes, net of federal benefit (4,196 ) (2,743 ) (1,414 ) Nondeductible expenses 405 396 218 Nondeductible stock-based compensation 4,808 5,293 1,469 Research and development credits (3,284 ) (2,739 ) (1,609 ) Foreign operation (144 ) — — Change in valuation allowance 43,935 33,942 16,253 Other (29 ) 11 — Provision for income taxes $ 1,017 $ 837 $ 425
Significant Components of Net Deferred Tax Assets	The significant components of net deferred tax assets were as follows (in thousands): As of January 31, 2016 2015 Deferred tax assets: Net operating losses $ 62,578 $ 42,696 Depreciation 614 352 Accruals and reserves 9,038 8,090 Deferred revenue 15,819 6,748 Stock-based compensation 14,395 9,197 Research and development tax credits 9,612 6,427 Gross deferred tax assets 112,056 73,510 Depreciation and amortization (18 ) (11 ) Net deferred tax assets prior to valuation allowance 112,038 73,499 Valuation allowance (111,380 ) (73,235 ) Total net deferred tax assets $ 658 $ 264
Schedule of Net Operating Loss, or NOL, Carryforwards and Research and Development Credits	As of January 31, 2016, the Company had net operating loss, or NOL, carryforwards and research and development credits as follows (in thousands): Amount Expiration Year Net operating losses, federal $ 262,815 2028-2036 Net operating losses, state 188,759 2028-2036 Research and development credits, federal 9,102 2028-2036 Research and development credits, California 8,625 Indefinite Research and development credits, North Carolina 156 2029 - Indefinite
Reconciliation of Gross Unrecognized Tax Benefits Before Interest and Penalties	A reconciliation of the beginning and ending balances of gross unrecognized tax benefits, before interest and penalties is as follows (in thousands): Amount Balance as of January 31, 2013 1,083 Additions for tax positions related to prior year 9 Additions for tax positions related to current year 955 Reductions for tax positions related to prior year — Balance as of January 31, 2014 2,047 Additions for tax positions related to prior year 153 Additions for tax positions related to current year 1,594 Reductions for tax positions related to prior year (6 ) Balance as of January 31, 2015 $ 3,788 Additions for tax positions related to prior year 1,491 Additions for tax positions related to current year 2,206 Reductions for tax positions related to prior year (775 ) Balance as of January 31, 2016 $ 6,710

Segments (Tables)

Segments (Tables)	12 Months Ended
	Jan. 31, 2016
Segment Reporting [Abstract]
Schedule of Revenue by Region	Revenue by region, based on the bill to mailing address of the end-customer, for the periods presented was as follows (in thousands): Year Ended January 31, 2016 2015 2014 North America $ 253,307 $ 186,145 $ 107,305 EMEA 46,062 28,210 11,731 APAC 22,846 13,303 6,550 Other — 15 147 Total revenue $ 322,215 $ 227,673 $ 125,733
Schedule of Long-lived Assets	Long-lived assets located in the following countries and regions as of each period end were as follows (in thousands): As of January 31, 2016 2015 North America $ 47,277 $ 40,521 Other 881 433 Total long-lived assets $ 48,158 $ 40,954

Selected Quarterly Financial 31

Selected Quarterly Financial Data (unaudited) (Tables)	12 Months Ended
	Jan. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Summary of Selected Unaudited Quarterly Consolidated Statements of Operations	The following tables set forth selected unaudited quarterly consolidated statements of operations data for each of the eight quarters in fiscal 2016 and 2015 (in thousands, except per share data): Quarter Ended April 30, July 31, October 31, January 31, April 30, July 31, October 31, January 31, Net revenues $ 46,547 $ 53,761 $ 59,096 $ 68,269 $ 71,288 $ 80,109 $ 80,727 $ 90,091 Gross profit 30,212 35,245 38,432 44,831 46,495 52,345 52,690 58,050 Net loss $ (19,595 ) $ (26,117 ) $ (28,389 ) $ (24,745 ) $ (28,986 ) $ (30,109 ) $ (28,574 ) $ (32,400 ) Net loss per share, basic and diluted $ (0.28 ) $ (0.37 ) $ (0.39 ) $ (0.33 ) $ (0.38 ) $ (0.38 ) $ (0.36 ) $ (0.40 )

Description of Business and B32

Description of Business and Basis of Presentation - Additional Information (Detail)	12 Months Ended
	Jan. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business entity, date of incorporation	2007-11
Business entity state of incorporation	State of Delaware

Summary of Significant Accoun33

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	Jan. 31, 2016USD ($)	Jan. 31, 2014Distributor	Oct. 31, 2013Distributor	Jan. 31, 2016USD ($)	Jan. 31, 2015USD ($)	Jan. 31, 2014USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of major distributors | Distributor		3	3
Foreign currency re-measurement net losses				$ 700	$ 2,100	$ 100
Cash and cash equivalents maturity period				90 days
Restricted cash, Current	$ 793			$ 793	0
Restricted cash, non-current	74			74	3,983
Allowance for doubtful accounts	25			25	0
Service inventory held at service depots	5,600			5,600	4,100
Inventory reserves	$ 4,500			4,500	2,300
Weighted average remaining contract period related to non-current deferred revenue	2 years 2 months 12 days
Advertising costs				$ 6,600	3,000	$ 1,200
Foreign currency forward contracts, maturity period				1 month
Employee Medical and Dental Self-funded Reimbursement Plan [Member]
Summary Of Significant Accounting Policies [Line Items]
Restricted cash, Current	$ 793			$ 793
Foreign Currency Forward Contracts [Member]
Summary Of Significant Accounting Policies [Line Items]
Gains related to foreign currency forward contracts				$ 200	$ 700
Employee Stock Options [Member]
Summary Of Significant Accounting Policies [Line Items]
Stock-based compensation expense requisite service period	4 years
Minimum [Member] | Accounts Receivable [Member] | Customer Concentration Risk [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, Percentage				10.00%
Minimum [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, Percentage				10.00%
Minimum [Member] | Employee Stock Purchase Plan [Member]
Summary Of Significant Accounting Policies [Line Items]
Stock-based compensation expense requisite service period	6 months
Maximum [Member] | Employee Stock Purchase Plan [Member]
Summary Of Significant Accounting Policies [Line Items]
Stock-based compensation expense requisite service period	2 years
Letter of Credit [Member]
Summary Of Significant Accounting Policies [Line Items]
Restricted cash, non-current	$ 3,900			$ 3,900
Hardware Components [Member]
Summary Of Significant Accounting Policies [Line Items]
Standard product warranty period				1 year
Embedded Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Standard product warranty period				90 days

Summary of Significant Accoun34

Summary of Significant Accounting Policies - Percentage of Company's Accounts Receivable and Revenue (Detail) - Customer Concentration Risk [Member]	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Customer A [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage			16.00%
Accounts Receivable [Member] | Customer B [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage	26.00%	18.00%
Accounts Receivable [Member] | Customer C [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage		16.00%
Accounts Receivable [Member] | Customer A [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage	41.00%	44.00%
Sales Revenue, Net [Member] | Customer B [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage	22.00%
Sales Revenue, Net [Member] | Customer C [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage	16.00%	21.00%
Sales Revenue, Net [Member] | Customer A [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage	41.00%	48.00%

Summary of Significant Accoun35

Summary of Significant Accounting Policies - Percentage of Company's Accounts Receivable and Revenue (Parenthetical) (Detail) - Customer Concentration Risk [Member]	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Customer B [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage	26.00%	18.00%
Customer B [Member] | Sales Revenue, Net [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage	22.00%
Customer B [Member] | Maximum [Member] | Sales Revenue, Net [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage		10.00%	10.00%
Customer C [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage		16.00%
Customer C [Member] | Sales Revenue, Net [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage	16.00%	21.00%
Customer C [Member] | Maximum [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage	10.00%
Customer C [Member] | Maximum [Member] | Sales Revenue, Net [Member]
Concentration Risk [Line Items]
Concentration risk, Percentage			10.00%

Summary of Significant Accoun36

Summary of Significant Accounting Policies - Summary of Company's Inventories, Net of Inventory Provisions Recorded to Adjust Inventory to Estimated Realizable Value by Major Category (Detail) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Inventory Disclosure [Abstract]
Raw materials	$ 2,296	$ 2,383
Finished goods	9,005	6,871
Evaluation inventory	4,693	2,727
Total	$ 15,994	$ 11,981

Summary of Significant Accoun37

Summary of Significant Accounting Policies - Estimated Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Jan. 31, 2016
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	5 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life description	Shorter of estimated useful life or remaining lease term
Demonstration Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	2 years

Summary of Significant Accoun38

Summary of Significant Accounting Policies - Computation of Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Numerator:
Net loss	$ (32,400)	$ (28,574)	$ (30,109)	$ (28,986)	$ (24,745)	$ (28,389)	$ (26,117)	$ (19,595)	$ (120,069)	$ (98,846)	$ (43,123)
Add: accretion of redeemable convertible preferred stock									0	0	(36)
Net loss attributable to common stockholders									$ (120,069)	$ (98,846)	$ (43,159)
Denominator:
Weighted-average number of shares outstanding - basic and diluted									78,932	72,304	26,772
Net loss per share - basic and diluted	$ (0.40)	$ (0.36)	$ (0.38)	$ (0.38)	$ (0.33)	$ (0.39)	$ (0.37)	$ (0.28)	$ (1.52)	$ (1.37)	$ (1.61)

Summary of Significant Accoun39

Summary of Significant Accounting Policies - Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Detail) - shares shares in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Unvested restricted stock units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	9,902	5,743	626
Employee Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	8,593	12,360	16,329
Employee Stock Purchase Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	1,205	320	0
Unvested Early Exercised Common Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share	184	704	1,593

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Derivative Assets and Derivative Liabilities (Detail) - USD ($)	Jan. 31, 2016	Jan. 31, 2015
Forward Contracts Purchased [Member]
Derivative [Line Items]
Nominal Amount	$ 0	$ 0
Forward Contracts Purchased [Member] | Level 2 [Member]
Derivative [Line Items]
Fair Value Gain (Loss)	0	0
Forward Contracts Sold [Member]
Derivative [Line Items]
Nominal Amount	14,535,000	17,324,000
Forward Contracts Sold [Member] | Level 2 [Member]
Derivative [Line Items]
Fair Value Gain (Loss)	$ 58,000	$ (59,000)

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 76,206	$ 50,664
Less: accumulated depreciation	(28,802)	(13,948)
Total property and equipment, net	47,404	36,716
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	14,012	9,226
Lab Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	28,734	17,768
Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	5,470	3,443
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	4,497	3,287
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	17,514	14,461
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	3,692	1,223
Demonstration Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 2,287	$ 1,256

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Property, Plant and Equipment [Line Items]
Depreciation expense related to property and equipment	$ 15,598	$ 8,753	$ 4,177
Software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of property and equipment	3 years

Employee Loans - Additional Inf

Employee Loans - Additional Information (Detail) $ in Millions	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2013USD ($)Employees	Jan. 31, 2012USD ($)Employees
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of employees to whom recourse loans issued | Employees		2	2
Principal loan amount and accrued interest		$ 1.6
Loan and related interest repayment period	2013-08
First Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of loan issued to employees			$ 1
Percentage of interest rate for loan issued to employees			1.30%
Loan repayable description	The loan was contractually due and payable in full in December 2020 or upon such earlier date that the Company files a registration statement related to an initial public offering.
Second Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of loan issued to employees		$ 0.4
Percentage of interest rate for loan issued to employees		2.30%
Loan repayable description	The loan was contractually due and payable in full in June 2020 or upon such earlier date that the Company files a registration statement related to an initial public offering.

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	1 Months Ended			12 Months Ended
	Dec. 31, 2014USD ($)	Jul. 31, 2014USD ($)	Apr. 30, 2013USD ($)	Jan. 31, 2016USD ($)Claims	Jan. 31, 2015USD ($)	Jan. 31, 2014USD ($)	Apr. 30, 2015USD ($)
Other Commitments [Line Items]
Rent expense				$ 6.2	$ 5.3	$ 3.1
Contractual obligation				$ 36.4
Tenant improvement allowances received						$ 4.9
Number of claims pending | Claims				3
San Jose, California Office [Member]
Other Commitments [Line Items]
Contractual obligation			$ 35.5
Operating lease collateral in the form of a letter of credit			$ 3.9
Lease term optional extension period			60 months
Term of operating lease			96 months
Lease commencement date			Nov. 1, 2013
North Carolina Office [Member]
Other Commitments [Line Items]
Contractual obligation		$ 5
Tenant improvement allowances received	$ 1			$ 1.4
Operating lease collateral in the form of a letter of credit		$ 0.9					$ 1.1
Term of operating lease		84 months
Lease commencement date	Feb. 1, 2016	Aug. 1, 2014

Commitments and Contingencies45

Commitments and Contingencies - Future Minimum Commitments Under Operating Leases (Detail) $ in Thousands	Jan. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,017	$ 7,732
2,018	7,203
2,019	6,985
2,020	6,940
2,021	7,110
Thereafter	6,506
Future minimum commitments under operating leases	$ 42,476

Common Stock - Additional Infor

Common Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2013	Jan. 31, 2014	Jan. 31, 2016	Jan. 31, 2015	Dec. 18, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net cash proceeds from initial public offering	$ 175.4
Common stock, shares authorized			750,000,000	750,000,000
Common stock, par value			$ 0.001	$ 0.001
Preferred stock, shares authorized			5,000,000	5,000,000
Preferred stock, par value			$ 0.001	$ 0.001
Amendment [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized capital after amendment					755,000,000
Common stock, shares authorized					750,000,000
Common stock, par value					$ 0.001
Preferred stock, shares authorized					5,000,000
Preferred stock, par value					$ 0.001
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock outstanding converted into shares of common stock	38,900,000
Initial Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Initial public offering shares	9,200,000
Initial public offering price per share	$ 21
Initial Public Offering [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Initial public offering shares		9,200,000

Common Stock - Summary of Reser

Common Stock - Summary of Reserved Shares of Authorized but Unissued Common Stock (Detail) - shares	Jan. 31, 2016	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved for authorized but unissued common stock	27,877,000	10,200,000
Issued and outstanding stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved for authorized but unissued common stock	8,593,000
Unvested restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved for authorized but unissued common stock	9,902,000
Equity incentive plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved for authorized but unissued common stock	6,806,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved for authorized but unissued common stock	2,576,000

Equity Incentive Plans - Additi

Equity Incentive Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		12 Months Ended
	Sep. 30, 2013	May. 31, 2008	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum shares available for issuance			6,826,000	8,549,000
Total number of common stock outstanding			8,593,000	12,360,000
Shares authorized	10,200,000		27,877,000
Employee stock purchase plan, description			Common stock will be issued to participating employees at a price per share equal to 85% of the lesser of (a) the fair market value on the offering date, or (b) the fair market value on the purchase date.
Number of shares subject to repurchase			200,000	700,000
Liability incurred on stock repurchase			$ 700	$ 2,100
Intrinsic value of exercised options			63,100	89,100	$ 10,000
Fair value of stock option vested			$ 8,400	$ 11,400	$ 3,900
Stock options issued during the period			0
Weighted-average fair value, option granted				$ 14.52	$ 3.94
Total stock-based compensation expense			$ 83,304	$ 57,067	$ 9,149
Unrecognized stock based compensation expense, stock options			$ 9,200
Unrecognized stock based compensation expense, period			1 year 7 months 6 days
Unrecognized stock based compensation expense, equity instruments other than options			$ 1,800
Unrecognized stock based compensation expense, stock purchase rights, period			2017-09
Dividend yield			0.00%
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant			2,600,000
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value, equity instruments other than options granted			$ 19.61	$ 31.30	$ 18.92
Unrecognized stock based compensation expense, period			2 years 9 months 18 days
Unrecognized stock based compensation expense, equity instruments other than options			$ 183,400
Stock Purchase Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value, equity instruments other than options granted			$ 7.04	$ 7.20	$ 6.91
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense			$ 5,000	$ 7,200
2008 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share awards and options expiration period		10 years
Share awards and options vesting period		4 years
Stock vesting percentage		25.00%
Share awards and options, vesting terms			Grants to new employees generally vest over a four-year period, at a rate of 25% one year from the date the optionee's service period begins and 1/48 monthly thereafter.
Maximum shares available for issuance		55,600,000
Termination of equity incentive plan			2013-12
Total number of common stock outstanding			8,800,000
Shares available for future grant			0
2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share awards and options expiration period	10 years
Share awards and options vesting period	4 years
Maximum shares available for issuance	300,000,000
Termination of equity incentive plan			2023-09
Total number of common stock outstanding			9,700,000
Shares available for future grant			6,800,000
Plan, effective date			Dec. 12, 2013
Shares granted price, percentage	100.00%
Plan modification, description			The number of shares available for grant and issuance under the 2013 Plan will automatically increase on February 1st of each of the calendar years 2014 through 2022, by the lesser of (i) 5% of the number of shares issued and outstanding on each January 31stimmediately prior to the date of increase or (ii) such number of shares determined by the Company's board of directors.
2013 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum shares available for issuance	30,000,000
Plan, effective date			Dec. 12, 2013
Shares granted price, percentage	85.00%
Shares authorized	2,000,000
Plan modification, description			The number of shares of common stock reserved for issuance will automatically increase on February 1st of each calendar year, by an amount equal to (i) 1% of the total number of outstanding shares of common stock and common stock equivalents on the immediately preceding January 31st, or (ii) such lesser number of shares of common stock as determined by the Company's board of directors.
Employee stock purchase plan, offering period, description			Except for the initial offering period, each offering period is for 24 months beginning March 10th and September 10th of each year, with each such offering period consisting of four six-month purchase periods. The initial offering period began December 12, 2013 and ended on March 9, 2016, with purchase dates on September 9, 2014, March 9, 2015, September 9, 2015 and March 9, 2016.
Initial offering period beginning			Dec. 12, 2013
Initial offering period ending			Mar. 9, 2016
Payroll deductions, minimum percentage	1.00%
Payroll deductions, maximum percentage	15.00%

Equity Incentive Plans - Schedu

Equity Incentive Plans - Schedule of Stock Option and RSU Award Activity (Detail) - $ / shares shares in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Shares Available for Grant, Beginning balance	8,549
Shares Available for Grant, Additional options and RSUs authorized for issuance	3,810
Shares Available for Grant, Options exercised	0
Shares Available for Grant, Options canceled	497
Shares Available for Grant, Options repurchased	29
Outstanding RSUs, RSUs granted	(6,879)
Outstanding RSUs, RSUs vested	0
Outstanding RSUs, RSUs canceled	820
Shares Available for Grant, Ending balance	6,826	8,549
Shares Subject to Outstanding Options, Beginning balance	12,360
Shares Subject to Outstanding Options, Options exercised	(3,270)
Shares Subject to Outstanding Options, Options canceled	(497)
Shares Subject to Outstanding Options, Options repurchased	0
Shares Subject to Outstanding Options, Ending balance	8,593	12,360
Weighted-Average Exercise Price, Beginning balance	$ 3.16
Weighted-Average Exercise Price, Options exercised	2.52
Weighted-Average Exercise Price, Options canceled	4.60
Weighted-Average Exercise Price, Ending balance	$ 3.32	$ 3.16
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Outstanding RSUs, Beginning balance	5,743
Outstanding RSUs, RSUs granted	6,879
Outstanding RSUs, RSUs vested	(1,920)
Outstanding RSUs, RSUs canceled	(820)
Outstanding RSUs, Ending balance	9,882	5,743
Weighted-Average Grant Date Fair Value, Beginning balance	$ 30.07
Weighted-Average Grant Date Fair Value, RSUs granted	19.61	$ 31.30	$ 18.92
Weighted-Average Grant Date Fair Value, RSUs vested	30.37
Weighted-Average Grant Date Fair Value, RSUs canceled	29.58
Weighted-Average Grant Date Fair Value, Ending balance	$ 22.70	$ 30.07

Equity Incentive Plans - Sche50

Equity Incentive Plans - Schedule of Stock Options Outstanding (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 31, 2016USD ($)$ / sharesshares
Compensation Related Costs [Abstract]
Number of Shares Subject to Options, Vested and expected to vest | shares	8,428
Number of Shares Subject to Options, Exercisable | shares	8,014
Weighted-Average Exercise Price, Vested and expected to vest | $ / shares	$ 3.27
Weighted-Average Exercise Price, Exercisable | $ / shares	$ 2.98
Weighted-Average Remaining Contractual Term (Years), Vested and expected to vest	6 years 5 months 23 days
Weighted-Average Remaining Contractual Term (Years), Exercisable	6 years 4 months 28 days
Aggregate Intrinsic Value, Vested and expected to vest | $	$ 29,364
Aggregate Intrinsic Value, Exercisable | $	$ 29,619

Equity Incentive Plans - Compon

Equity Incentive Plans - Components of Stock-based Compensation Expense Related to Stock Options, RSUs and ESPP (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 83,304	$ 57,067	$ 9,149
Cost of Product Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	1,972	1,508	232
Cost of Support and Service Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	4,743	2,380	468
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	23,259	15,137	3,049
Sales and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	39,648	27,752	3,674
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 13,682	$ 10,290	$ 1,726

Equity Incentive Plans - Sche52

Equity Incentive Plans - Schedule of Call Option Valued Using Black-Scholes-Merton Option-Pricing Model - Stock Purchase Rights (Detail)	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%
Stock Purchase Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Volatility, minimum	29.00%	32.00%	43.00%
Volatility, maximum	35.00%	47.00%	48.00%
Risk-free interest rate, minimum	0.10%	0.10%	0.10%
Risk-free interest rate, maximum	0.80%	0.60%	0.40%
Dividend yield	0.00%	0.00%	0.00%
Stock Purchase Rights [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 months	6 months	9 months 18 days
Stock Purchase Rights [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	2 years	2 years	2 years 3 months 18 days

401 (k) Plan - Additional Infor

401 (k) Plan - Additional Information (Detail)	12 Months Ended
	Jan. 31, 2016USD ($)
Defined Contribution Pension and Other Postretirement Plans Disclosure [Abstract]
Discretionary employer matching contribution on behalf of employees	$ 0

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for income taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Income Tax Disclosure [Abstract]
U.S. operations	$ (122,116)	$ (100,136)	$ (44,007)
Non-U.S. operations	3,064	2,127	1,309
Loss before provision for income taxes	$ (119,052)	$ (98,009)	$ (42,698)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Income Tax Contingency [Line Items]
Provision for income taxes	$ 1,017,000	$ 837,000	$ 425,000
Changes in valuation allowance	38,100,000
Deferred tax liability	0
Undistributed earnings of foreign subsidiaries	4,600,000
Effect of unrecognized tax benefits on effective tax rate	410,000	$ 39,000
Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Tax benefits from stock options	97,300,000
California [Member]
Income Tax Contingency [Line Items]
Tax benefits from stock options	$ 22,900,000

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Tax Rate Differs from U.S. Federal Statutory Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Effective Income Tax Rate Reconciliation, Amount [Abstract]
U.S. federal taxes at statutory tax rate	$ (40,478)	$ (33,323)	$ (14,492)
State taxes, net of federal benefit	(4,196)	(2,743)	(1,414)
Nondeductible expenses	405	396	218
Nondeductible stock-based compensation	4,808	5,293	1,469
Research and development credits	(3,284)	(2,739)	(1,609)
Foreign operation	(144)	0	0
Change in valuation allowance	43,935	33,942	16,253
Other	(29)	11
Provision for income taxes	$ 1,017	$ 837	$ 425

Income Taxes - Significant Comp

Income Taxes - Significant Components of Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Deferred tax assets:
Net operating losses	$ 62,578	$ 42,696
Depreciation	614	352
Accruals and reserves	9,038	8,090
Deferred revenue	15,819	6,748
Stock-based compensation	14,395	9,197
Research and development tax credits	9,612	6,427
Gross deferred tax assets	112,056	73,510
Depreciation and amortization	(18)	(11)
Net deferred tax assets prior to valuation allowance	112,038	73,499
Valuation allowance	(111,380)	(73,235)
Total net deferred tax assets	$ 658	$ 264

Income Taxes - Schedule of Net

Income Taxes - Schedule of Net Operating Loss, or NOL, Carryforwards and Research and Development Credits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015
Income Tax Contingency [Line Items]
Research and development credits, Amount	$ 9,612	$ 6,427
California [Member]
Income Tax Contingency [Line Items]
Research and development credits, Amount	8,625
North Carolina [Member]
Income Tax Contingency [Line Items]
Research and development credits, Amount	$ 156
Minimum [Member] | North Carolina [Member]
Income Tax Contingency [Line Items]
Research and development credits, Expiry year	2,029
Maximum [Member] | California [Member]
Income Tax Contingency [Line Items]
Research and development credits, Expiry year	Indefinite
Maximum [Member] | North Carolina [Member]
Income Tax Contingency [Line Items]
Research and development credits, Expiry year	Indefinite
Federal [Member]
Income Tax Contingency [Line Items]
Net operating losses, Amount	$ 262,815
Research and development credits, Amount	$ 9,102
Federal [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Net operating losses, Expiry year	2,028
Research and development credits, Expiry year	2,028
Federal [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Net operating losses, Expiry year	2,036
Research and development credits, Expiry year	2,036
State [Member]
Income Tax Contingency [Line Items]
Net operating losses, Amount	$ 188,759
State [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
Net operating losses, Expiry year	2,028
State [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
Net operating losses, Expiry year	2,036

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Gross Unrecognized Tax Benefits Before Interest and Penalties (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense [Abstract]
Beginning Balance	$ 3,788	$ 2,047	$ 1,083
Additions for tax positions related to prior year	1,491	153	9
Additions for tax positions related to current year	2,206	1,594	955
Reductions for tax positions related to prior year	(775)	(6)	0
Ending Balance	$ 6,710	$ 3,788	$ 2,047

Segments - Additional Informati

Segments - Additional Information (Detail)	12 Months Ended
	Jan. 31, 2016Segment
Segment Reporting [Abstract]
Number of business activity	1
Number of reporting segments	1

Segments - Schedule of Revenue

Segments - Schedule of Revenue by Region (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 90,091	$ 80,727	$ 80,109	$ 71,288	$ 68,269	$ 59,096	$ 53,761	$ 46,547	$ 322,215	$ 227,673	$ 125,733
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									253,307	186,145	107,305
EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									46,062	28,210	11,731
APAC [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									22,846	13,303	6,550
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$ 0	$ 15	$ 147

Segments - Schedule of Long-liv

Segments - Schedule of Long-lived Assets (Detail) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 48,158	$ 40,954
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	47,277	40,521
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 881	$ 433

Line of Credit - Additional Inf

Line of Credit - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Jan. 31, 2016	Jan. 31, 2016	Apr. 30, 2015	Jan. 31, 2015	Jul. 31, 2014	Oct. 31, 2013
Line of Credit Facility [Line Items]
Line of credit facility unused portion commitment fee		0.20%
Line of credit facility renewal date		2014-09
Line of credit facility incremental period		2 years
Line of credit facility expiration date		2016-10
Minimum tangible net worth limit	$ 135,000,000	$ 135,000,000
Remaining Credit Facility available for borrowings	10,000,000	$ 10,000,000
Minimum current ratio		125.00%
Restricted cash, non-current	74,000	$ 74,000		$ 3,983,000
Wells Fargo Bank, National Association [Member]
Line of Credit Facility [Line Items]
Line of credit facility financial covenants		(i) maintain minimum tangible net worth, defined as the aggregate of total stockholders' equity plus subordinated debt less any intangible assets and less any loans or advances to, or investments in, any related entities or individuals, of $135 million; and (ii) maintain a monthly ratio of not less than 1.25 to 1.00, based on the aggregate of its cash and net accounts receivable divided by total current liabilities minus current deferred revenue.
Credit Facility, current amount outstanding	0	$ 0
Line of credit facility maximum borrowing capacity						$ 15,000,000
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Reduction of available line related to Letter of Credit issued	(3,900,000)
Restricted cash, non-current	$ 3,900,000	$ 3,900,000
North Carolina Office [Member]
Line of Credit Facility [Line Items]
Operating lease collateral in the form of a letter of credit			$ 1,100,000		$ 900,000

Selected Quarterly Financial 64

Selected Quarterly Financial Data (unaudited) (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Net revenues	$ 90,091	$ 80,727	$ 80,109	$ 71,288	$ 68,269	$ 59,096	$ 53,761	$ 46,547	$ 322,215	$ 227,673	$ 125,733
Gross profit	58,050	52,690	52,345	46,495	44,831	38,432	35,245	30,212	209,580	148,720	81,522
Net loss	$ (32,400)	$ (28,574)	$ (30,109)	$ (28,986)	$ (24,745)	$ (28,389)	$ (26,117)	$ (19,595)	$ (120,069)	$ (98,846)	$ (43,123)
Net loss per share, basic and diluted	$ (0.40)	$ (0.36)	$ (0.38)	$ (0.38)	$ (0.33)	$ (0.39)	$ (0.37)	$ (0.28)	$ (1.52)	$ (1.37)	$ (1.61)