Stockholders' equity (Tables)

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Common Stock Reserved for Future Issuance

Shares of common stock reserved for future issuance consisted of the following:

	September 30,	December 31,
	2023	2022
2010 Equity Incentive Plan:
Stock options outstanding	7,569,747	10,333,771
2021 Equity Incentive Plan:
RSUs outstanding and PSUs(1)	18,270,292	16,178,101
Shares available for future issuance under:
2021 Equity Incentive Plan	3,714,081	2,814,126
2021 Employee Stock Purchase Plan	2,754,604	1,929,578
Total shares of common stock reserved	32,308,724	31,255,576
(1) The number of PSUs reserved for issuance is based on the maximum achievement of the corporate performance metric.

Summary of Option Activity

The following is a summary of activity for stock options having only service-based vesting conditions under the Equity Incentive Plans:

	Options Outstanding	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value (In Thousands)
Balance - December 31, 2022	10,283,771	$	4.18	6.38	$	66,234
Granted	—	—
Exercised	(2,540,719)	3.40
Canceled	(223,305)	7.60
Balance - September 30, 2023	7,519,747	$	4.35	2.55	$	39,357
Vested & expected to vest as of September 30, 2023	7,519,747	$	4.35	2.55	$	39,357
Exercisable as of September 30, 2023	7,181,202	$	4.20	2.51	$	38,489

Summary of Stock Appreciation Rights

The following is a summary of activity for SARs under the Equity Incentive Plans:

	SARs Outstanding	Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value (In Thousands)
Balance - December 31, 2022	81,770	$	5.44	6.90	$	418
Granted	—	—
Exercised	(67,781)	5.30
Canceled	(9,289)	6.58
Balance - September 30, 2023	4,700	$	5.11	6.23	$	21
Vested & expected to vest as of September 30, 2023	4,700	$	5.11	6.23	$	21
Exercisable as of September 30, 2023	4,389	$	5.00	6.21	$	20

Summary of Restricted Stock Unit Activity

A summary of RSU and PSU activity under the 2021 Plan is as follows:

	RSUs Outstanding	Weighted Average Grant Date Fair Value		PSUs Outstanding	Weighted Average Grant Date Fair Value
Unvested - December 31, 2022	16,178,101	$	17.37	—	$	—
Granted	7,615,860	$	9.62	645,833	$	8.89
Released	(4,481,848)	$	16.58	—	$	—
Canceled	(2,010,553)	$	16.11	—	$	—
Unvested - September 30, 2023	17,301,560	$	14.31	645,833	$	8.89

Summary of Performance-Based Options

A summary of RSU and PSU activity under the 2021 Plan is as follows:

	RSUs Outstanding	Weighted Average Grant Date Fair Value		PSUs Outstanding	Weighted Average Grant Date Fair Value
Unvested - December 31, 2022	16,178,101	$	17.37	—	$	—
Granted	7,615,860	$	9.62	645,833	$	8.89
Released	(4,481,848)	$	16.58	—	$	—
Canceled	(2,010,553)	$	16.11	—	$	—
Unvested - September 30, 2023	17,301,560	$	14.31	645,833	$	8.89

Summary of Weighted Average Assumptions, Options

The following table summarizes the weighted-average assumptions used in the Black-Scholes option-pricing model to estimate the fair value of employee stock purchase rights granted under the new ESPP offering period:

	Nine Months Ended September 30, 2023
Risk-free interest rate	4.5%
Expected volatility	69.7%
Expected life (in years)	1.6
Expected dividend yield	—%

Summary of Stock-Based Compensation Expense

Total stock-based compensation expense included in the condensed consolidated statements of operations was as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Cost of revenue	$	1,788	$	1,611	$	5,130	$	3,440
Sales and marketing	7,646		9,372		23,022		18,516
Research and development	7,045		6,258		19,762		13,303
General and administrative	7,005		7,728		23,806		17,784
Restructuring charges	—		—		1,208		—
Total stock-based compensation expense	$	23,484	$	24,969	$	72,928	$	53,043