Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement [Abstract]

Schedule of Stock-based Awards

The following table summarizes the stock options activity under the 2010 Plan and 2019 Plan for the three months ended March 31, 2020:

	Stock Options Outstanding
	(in thousands, except year and per share data)
	Shares Subject to Options Outstanding	Weighted- Average Exercise Price per Option		Weighted- Average Remaining Contractual Terms (in years)	Aggregate Intrinsic Value
Balances as of December 31, 2019	21,191	$	2.30	7.4	$	312,720
Options granted	1,700	$	17.93
Options exercised	(1,518)	$	1.78		$	26,551
Options canceled/forfeited/expired	(104)	$	2.45
Balances as of March 31, 2020	21,269	$	3.59	7.5	$	422,728
Vested and expected to vest as of March 31, 2020	21,269	$	3.59	7.5	$	422,728
Exercisable as of March 31, 2020	19,566	$	2.34	7.3	$	413,239

Schedule of Assumptions Used to Determine the Fair Value of Stock Options Granted

The weighted-average assumptions used to determine the fair value of stock options granted during the periods presented were as follows:

	Three Months ended March 31,
	2020		2019
Expected term (in years)	6.1		6.3
Expected volatility	40.0	%	40.3	%
Risk-free interest rate	1.5	%	2.6	%
Dividend yield	—		—

Schedule of Restricted Stock Units Activity

RSU activity for the three months ended March 31, 2020 was as follows:

	Restricted Stock and RSUs	Weighted-Average Grant Date Fair Value
	(in thousands, except per share data)
Unvested and outstanding as of December 31, 2019	6,508	$	11.08
Granted - RSUs	1,103	$	17.93
Granted - Restricted stock	841	$	17.06
Vested - RSUs	(494)	$	9.66
Forfeited	(142)	$	10.28
Unvested as of March 31, 2020	7,816	$	11.85
Vested and not yet released	7	$	8.75
Outstanding as of March 31, 2020	7,823	$	11.85

Schedule of Fair Value Assumptions for Employee Stock Purchase Plan

The weighted-average assumptions used to determine the fair value of the ESPP during the periods presented were as follows:

	Three Months ended March 31,
	2020		2019
Expected term (in years)	0.6		N/A
Risk-free interest rate	1.8	%	N/A
Expected volatility	35.5	%	N/A
Dividend yield	—		N/A

Schedule of Stock-based Compensation Expense

The following table sets forth the total stock-based compensation expense included in the Company’s condensed consolidated statements of operations:

	Three Months Ended March 31,
	2020		2019
	(in thousands)
Cost of revenue	$	267	$	32
Sales and marketing	3,163		279
Research and development	6,090		417
General and administrative	3,377		329
Total stock-based compensation expense	$	12,897	$	1,057