Stock-Based Compensation (Tables)

9 Months Ended

Oct. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Option Activity Under Equity Incentive Plans and Related Information

The following table summarizes the stock option activity under the equity incentive plans and related information:

	Shares Subject to Options Outstanding					Weighted- Average
				Weighted-		Remaining
				Average Exercise		Contractual Life		Aggregate
	Shares			Price		(Years)		Intrinsic Value
								(in thousands)
Balance as of January 31, 2019		9,096,961		$	9.01		4.97	$	108,731
Options granted		577,082			19.89
Options exercised		(417,245	)		7.21
Options forfeited/cancelled		(60,972	)		18.00
Balance as of October 31, 2019		9,195,826		$	9.71		4.55	$	72,392
Vested and expected to vest as of October 31, 2019		9,119,519		$	9.63		4.51	$	72,389
Exercisable as of October 31, 2019		7,579,160		$	7.60		3.68	$	72,342

Summary of Restricted Stock Unit Activity Under Equity Incentive Plans and Related Information

The following table summarizes the restricted stock unit activity under the equity incentive plans and related information:

	Number of			Weighted-
	Restricted			Average
	Stock Units			Grant Date
	Outstanding			Fair Value
Unvested balance - January 31, 2019		18,098,707		$	19.35
Granted		11,032,086			19.02
Vested, net of shares withheld for employee payroll taxes		(3,275,859	)		20.00
Forfeited/cancelled		(3,320,045	)		19.68
Unvested balance - October 31, 2019		22,534,889		$	19.04

Summary of Components of Stock-Based Compensation Expense

The following table summarizes the components of stock-based compensation expense recognized in the condensed consolidated statements of operations (in thousands):

	Three Months Ended				Nine Months Ended
	October 31,				October 31,
	2019		2018		2019		2018
Cost of revenue	$	4,428	$	3,598	$	12,399	$	10,280
Research and development		16,653		12,043		44,878		33,668
Sales and marketing		9,250		9,708		28,644		27,701
General and administrative		7,427		6,441		21,004		17,437
Total stock-based compensation	$	37,758	$	31,790	$	106,925	$	89,086

Summary of Estimated Fair Value of Employee Stock Options and 2015 ESPP

We estimated the fair value of employee stock options and 2015 ESPP purchase rights using a Black-Scholes option pricing model with the following assumptions.

	Three Months Ended													Nine Months Ended
	October 31,													October 31,
	2019							2018						2019						2018
Employee Stock Options
Expected term (in years)					N/A							5.8			5.5		-	5.8			5.5		-	5.8
Risk-free interest rate					N/A							3.1	%					1.8	%		2.8	%	-	3.1	%
Volatility					N/A							45	%					45	%					45	%
Dividend yield					N/A							0	%					0	%					0	%
Employee Stock Purchase Plan
Expected term (in years)		0.5		-		2.0			0.5		-	2.0			0.5		-	2.0			0.5		-	2.0
Risk-free interest rate		1.7	%	-		1.9	%		2.3	%	-	2.8	%		1.7	%	-	2.5	%		2.0	%	-	2.8	%
Volatility		34	%	-		47	%		40	%	-	48	%		34	%	-	55	%		37	%	-	50	%
Dividend yield						0	%					0	%					0	%					0	%