Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Total Stock-based Compensation

Total stock-based compensation is as follows:

	Year ended December 31,
	2022		2021		2020
	(in thousands)
Cost of revenue	$	126	$	738	$	60
Research and development		1,039		6,939		822
Sales and marketing		2,720		11,213		1,629
General and administrative		6,080		8,841		2,578
Total stock-based compensation	$	9,965	$	27,731	$	5,089

Summary of Stock Option Activity

Stock option activity for the year ended December 31, 2022 is set forth below:

	Number of shares			Weighted average exercise price		Weighted average remaining contractual term		Aggregate intrinsic value
						(in years)		(in thousands)
Balance December 31, 2021		270,195		$	97.36		7.88	$	12,860
Grants		64,391			26.62
Exercises		(3,026	)		44.42
Cancelled or forfeited		(22,245	)		112.23
Balance December 31, 2022		309,315		$	82.08		5.60	$	—
Vested and exercisable as of December 31, 2022		213,131		$	70.51		5.33	$	—

Assumptions used in Estimating Grant-Date Fair Value of Stock-based Awards Using Black-Scholes Option Pricing Model

The estimated grant-date fair value of the Company’s stock options was calculated using the Black-Scholes option pricing model, based on the following assumptions:

	Year ended December 31,
Valuation assumptions:	2022	2021	2020
Expected volatility	59% - 60%	53%-57%	60%-71%
Expected term	5.2 - 5.8 years	5.8-6.7 years	5.1-7.0 years
Risk-free interest rate	3.18% - 4.01%	0.62%-1.11%	0.23%-1.20%
Dividend yield	—	—	—

Schedule of RSU Activity

RSU activity for the year ended December 31, 2022 is set forth below:

	Number of shares			Weighted average grant date fair value per share
Balance December 31, 2021		17,458		$	866.76
RSUs granted		181,995			59.59
RSUs vested		(9,992	)		495.48
RSUs forfeited		(13,398	)		232.09
Balance December 31, 2022		176,063		$	101.76

Fair Value of ESPP Shares Estimated Using Black-Scholes Option Pricing Model

The fair value of the ESPP shares is estimated using the Black-Scholes option pricing model, based on the following assumptions for the offering period that started in May 2021:

	Year ended December 31,
Valuation assumptions:	2021
Expected volatility	44%-57%
Expected term	0.5-2.0 years
Risk-free interest rate	0.04%-0.16%
Dividend yield	—