Stock Plans and Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Schedule of Assumptions Used in Determining Fair Value of Shares Issuable

The fair value of shares issuable under the 2016 ESPP is determined using the Black-Scholes option pricing model with the following weighted-average assumptions:

	Year Ended December 31,
	2022	2021	2020
Employee Stock Purchase Plan:
Expected term (in years) (1)	0.50	0.50	0.50
Expected volatility (2)	65% - 70%	45% - 60%	55% - 65%
Risk-free interest rate (3)	0.85% - 3.33%	0.05% - 0.06%	0.12% - 0.29%
Dividend rate (4)	0%	0%	0%

(1)The expected term represents the contractual term of the 2016 ESPP;

(2)The expected volatility of the Company’s common stock on the date of grant is based on the weighted average of the Company’s historical volatility as a public company, the implied volatility of publicly-traded options on the Company’s common stock and the volatilities of publicly traded peer companies that are reasonably comparable to the Company’s own operations;

(3)The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero coupon U.S. Treasury notes with maturities approximately equal to the expected term of the grant; and

(4)The expected dividend yield is assumed to be zero as the Company has never paid dividends and has no current plans to pay any dividends on the Company’s common stock.

Schedule of Stock Option Activity

The following table summarizes the Company’s stock option activity:

	Stock options outstanding			Weighted average exercise price
Outstanding at December 31, 2021		157,740		$	23.83
Exercised		(9,883	)		14.58
Forfeited		(5,655	)		38.66
Outstanding at December 31, 2022		142,202			23.89

Schedule of Stock Options Outstanding, Vested and Expected to Vest and Exercisable

Stock options outstanding, vested and expected to vest and exercisable are as follows:

	As of December 31, 2022
	Number of shares		Remaining contractual life (years)		Weighted- average exercise price
Outstanding		142,202		4.15	$	23.89
Vested and expected to vest		142,202		4.15		23.89
Exercisable		142,202		4.15		23.89

Schedule of Vested and Nonvested Stock Option Activity

Vested and nonvested stock option activity was as follows:

	Vested				Nonvested
	Options outstanding		Weighted average exercise price		Options outstanding		Weighted average exercise price
Outstanding at December 31, 2022		142,202	$	23.89		—	$	—

Summary of RSU and PSU Activity

The following table summarizes the Company’s RSU and PSU activity:

	Number of Shares
Outstanding at December 31, 2021		1,579,738
Granted		3,641,018
Vested		(843,402	)
Forfeited		(1,144,056	)
Outstanding at December 31, 2022		3,233,298

Schedule of Assumptions used in Monte Carlo Simulation Model

Fair value of the market-based grants is determined using the Monte-Carlo simulation with the following assumptions:

	Year Ended December 31, 2022
Market-Based Grants:
Expected term (in years)	0.73 - 1.50
Expected volatility	58% - 71%
Risk-free interest rate	1.97% - 4.69%
Dividend rate	0%

Summary of Stock-Based Compensation Expense

The Company recorded the total stock-based compensation expense as follows (in thousands):

	Year Ended December 31,
	2022		2021		2020
Cost of revenue	$	5,468	$	3,678	$	2,966
Sales and marketing		15,917		15,936		15,836
Research and development		9,967		8,717		8,935
General and administrative		16,268		15,764		19,018
Total	$	47,620	$	44,095	$	46,755