Share Reserve. The number of shares of common stock available for issuance under the 2021 Equity Incentive Plan (“2021 Plan”) equals the sum of 5,262,500 shares plus up to approximately 13,719,000 shares subject to awards granted under the 2011 Plan that expire, forfeit or are repurchased following the effective date of the 2021 Plan. The number of shares reserved for issuance under the 2021 Plan will be increased automatically on the first business day of each of the Company’s fiscal years, commencing in 2022 and ending in 2031, by a number equal to the lowest of (i) 4,784,100 shares, (ii) 5% of the shares of common stock outstanding on the last business day of the prior fiscal year; or (iii) the number of shares determined by the Board of Directors. Pursuant to this evergreen provision, the Company increased the number of shares reserved under the 2021 Plan by 809,916 and 1,519,241 during the three months ended March 31, 2023 and 2022, respectively.

In general, to the extent that any awards under the 2021 Plan are forfeited, terminate, expire or lapse without the issuance of shares, or if the Company reacquires the shares subject to awards granted under the 2021 Plan, those shares will again become available for issuance under the 2021 Plan, as will shares applied to pay the exercise or purchase price of an award or to satisfy tax withholding obligations related to any award.

RSUs granted under the 2021 Equity Incentive Plan generally vest based on continued service over a three to four year period for employees, and over a one year period for non-employee directors. RSU’s granted pursuant to the Company’s bonus plan have immediate vesting, see the section titled Bonus Plan below.


	Shares	Weighted-average grant date fair value per share
Unvested balance as of December 31, 2022	3,716,061	$	6.60
Granted	989,283	$	5.97
Vested	(626,772)	$	6.87
Forfeited	(91,575)	$	5.61
Unvested balance as of March 31, 2023	3,986,997	$	6.42

The following table summarizes the Black-Scholes option pricing model weighted-average assumptions used in estimating the fair value of stock options granted to employees during the three months ended March 31, 2022. No stock options were granted during the three months ended March 31, 2023.

Expected term. For stock options considered to be “plain vanilla” options, the Company estimates the expected term based on the simplified method, which is essentially the weighted average of the vesting period and contractual term, as the Company’s historical share option exercise experience does not provide a reasonable basis upon which to estimate the expected term.

Expected volatility. The Company performed an analysis using the average volatility of a peer group of representative public companies with sufficient trading history over the expected term to develop an expected volatility assumption.

Risk-free interest rate. Based upon quoted market yields for the United States Treasury debt securities for a term consistent with the expected life of the awards in effect at the time of grant.


	Shares available for grant	Outstanding stock options	Weighted- average exercise Price		Weighted- average remaining contractual life (years)	Aggregate intrinsic value
Balance as of December 31, 2022	1,836,566	12,371,281	$	5.74	6.07	$	32,385
Shares authorized	809,916
Options granted	—	—	—
Options exercised	—	(496,905)	1.69
Options cancelled	110,449	(110,449)	12.90
RSU award activity	(897,708)	—

Balance as of March 31, 2023	1,859,223	11,763,927	$	5.84	5.85	$	20,684
Vested and exercisable as of March 31, 2023		8,755,570	$	4.15	5.08	$	19,219

No stock options were granted during the three months ended March 31, 2023. The weighted-average grant-date fair value of options granted was $13.29 during the three months ended March 31, 2022. The intrinsic value of options exercised for the three months ended March 31, 2023 and 2022 was $2.1 million and $4.1 million, respectively. Aggregate intrinsic value represents the difference between the exercise price of the options and the estimated fair value of the Company’s common stock at the time of exercise. The aggregate grant-date fair value of options vested was $2.3 million and $1.8 million during the three months ended March 31, 2023 and 2022, respectively.

In October 2021, the Company’s Board of Directors adopted the 2021 Employee Stock Purchase Plan (“ESPP”), which became effective on the date of the IPO. As of December 31, 2022, the ESPP reserved and authorized the issuance of up to a total of 1,564,496 shares of Class A common stock to participating employees. Pursuant to its evergreen provision, the Company increased the number of shares reserved under the ESPP by 667,874 and 607,696 during the three months ended March 31, 2023 and 2022, respectively.

There were no shares purchased during the three months ended March 31, 2023, as the first purchase date in 2023 will occur in May 2023. The fair value of the purchase rights under the ESPP was estimated using the Black-Scholes option pricing model with a similar methodology for determining inputs as the Company’s stock options, as described above. The Company recorded stock-based compensation expense under this plan of $1.0 million and $0.8 million for the three months ended March 31, 2023 and 2022, respectively, of which the Company capitalized $0.2 million and less than $0.1 million, respectively, of stock-based compensation expense under this plan for the development of internal-use software. As of March 31, 2023, the total unrecognized stock-based compensation expense related to the ESPP was $3.7 million and is

The following table summarizes the Black-Scholes option pricing model assumptions used in estimating the fair value of the stock purchase rights under the ESPP during the three months ended March 31, 2023 and 2022, respectively.


	Three Months Ended March 31,
	2023		2022
Expected term (in years)	0.5 - 2.0		0.5 - 2.0
Expected volatility	45% - 68%		45% - 57%
Risk-free interest rate	0.10% - 4.75%		0.10% - 0.51%
Expected dividend yield	—	%	—	%


	Three Months Ended March 31,
	2023		2022
Cost of revenue	$	416	$	276
Research and development	2,133		1,555
Sales and marketing	2,152		1,134
General and administrative	1,127		870
Total stock-based compensation expense	$	5,828	$	3,835

During the three months ended March 31, 2023 and 2022, the Company capitalized $1.0 million and $0.4 million, respectively, of stock-based compensation for the development of internal-use software. As of March 31, 2023, total compensation cost related to stock options and RSUs not yet vested was $18.2 million and $23.4 million, respectively, which will be recognized over a weighted-average period of two and three years for stock options and RSUs, respectively.

During March 2022, the Company’s Compensation Committee approved a new bonus structure (“Bonus Plan”) for its employees. The Bonus Plan is contingent upon the achievement of 2022 corporate performance targets. Pursuant to the Bonus Plan, during February 2023 the Company’s Compensation Committee approved the issuance of approximately 288,000 RSUs that immediately vested. The Company recognized $0.5 million in respective stock-based compensation during the three months ended March 31, 2022.

During February 2023, the Company’s Board of Directors approved 2023 corporate performance targets under its Bonus Plan for its employees. If these performance targets are met during 2023, employees will be paid out under the plan in RSUs in 2024. As a result, the Company recognized $0.6 million in stock-based compensation during the three months ended March 31, 2023 based on progress made towards these performance targets.