Employee Incentive Plans (Tables)

12 Months Ended

Jan. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Stock-based Compensation Expense by Award Type

Stock-based compensation expense by award type was as follows (in thousands):

	Year Ended January 31,
	2018		2017		2016
Stock options	$	24,186	$	17,127	$	9,832
RSUs	9,104		—		—
ESPP	7,111		—		—
Restricted stock awards	3,281		—		—
Restricted common stock	6,178		—		—
Total	$	49,860	$	17,127	$	9,832

Schedule of Stock-based Compensation Expense by Statement of Operations Location

Stock-based compensation expense was recorded in the following cost and expense categories in the Company’s consolidated statements of operations (in thousands):

	Year Ended January 31,
	2018		2017		2016
Cost of revenue:
Subscription	$	4,600	$	1,979	$	909
Professional services and other	3,137		1,283		553
Research and development	18,107		2,992		1,748
Sales and marketing	13,242		6,029		2,853
General and administrative	10,774		4,844		3,769
Total	$	49,860	$	17,127	$	9,832

Schedule of Stock Option Activity

A summary of the Company’s stock option activity and related information is as follows:

	Number of Options		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (in thousands)
Outstanding as of January 31, 2017	32,866,862		$	6.01	8.2	$	145,570
Granted	2,676,667		11.56
Exercised	(9,180,242	)	3.66
Canceled	(1,446,242	)	7.76
Outstanding as of January 31, 2018	24,917,045		$	7.37	7.6	$	550,173
As of January 31, 2018:
Vested and expected to vest	24,917,045		$	7.37	7.6	$	550,173
Vested and exercisable	10,205,493		$	5.33	6.9	$	246,189

Schedule of Black-Scholes Option Pricing Model Estimated Fair Value Assumptions

The Company used the Black-Scholes option pricing model to estimate the fair value of stock options granted with the following assumptions:

	Year Ended January 31,
	2018	2017	2016
Expected volatility	40% - 41%	40% - 44%	42% -  46%
Expected term (in years)	6.3 - 6.4	5.5 - 6.9	5.0 - 6.1
Risk-free interest rate	1.87% - 2.21%	1.13% - 2.28%	1.43% -  1.88%
Expected dividend yield	—	—	—

Schedule of Nonvested Restricted Stock Units Activity

A summary of the Company’s RSU activities and related information is as follows:

	Number of RSUs		Weighted- Average Grant Date Fair Value Per Share
Outstanding as of January 31, 2017	—		$	—
Granted	3,012,111		24.37
Vested	—		—
Forfeited	(149,182	)	24.15
Outstanding as of January 31, 2018	2,862,929		$	24.38

Schedule of ESPP Black-Scholes Option Pricing Model Estimated Fair Value Assumptions

The Company estimated the fair value of ESPP purchase rights using a Black-Scholes option pricing model with the following assumptions:

	As of  January 31, 2018
Expected volatility	32% - 38%
Expected term (in years)	0.5-1.2
Risk-free interest rate	0.95%-1.73%
Expected dividend yield	—