Stock-Based Compensation (Tables)

3 Months Ended

12 Months Ended

Mar. 31, 2022

Dec. 31, 2021

Share-Based Payment Arrangement [Abstract]

Schedule of stock option activity

	Number of Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2021		—
Granted		4,347,492		5.15
Exercised		—
Cancelled/forfeited		—
Outstanding as of March 31, 2022		4,347,492	$	5.15		9.79	$	498

	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2021		31,962,921		$	2.81		7.77	$	86,075
Granted		—
Exercised		(268,702	)		2.50				729
Cancelled/forfeited		(1,049,835	)		3.40
Outstanding as of March 31, 2022		30,644,384		$	2.79		7.34	$	73,051

	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2021		9,526,727		$	5.55		8.0	$	13,905
Granted		—
Exercised		(492,973	)		2.41				1,037
Cancelled/forfeited		(243,815	)		8.02
Outstanding as of March 31, 2022		8,789,939		$	5.74		8.4	$	10,759

	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2020		30,402,801		$	2.45		8.75	$	885
Granted		5,287,031			4.74
Exercised		(2,757,671	)		2.30				7,740
Expired/forfeited		(969,240	)		3.65
Outstanding as of December 31, 2021		31,962,921		$	2.81		7.77	$	86,075
Exercisable as of December 31, 2021		14,777,334		$	2.51		6.93	$	41,622
Vested and expected to vest as of December 31, 2021		26,660,149		$	2.73		7.59	$	72,705

	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2020		6,490,208		$	2.49		9.26	$	1,174
Granted		5,516,399			7.82
Exercised		(1,630,925	)		2.54				8,807
Expired/Forfeited		(848,955	)		2.68
Outstanding as of December 31, 2021		9,526,727		$	5.55		8.01	$	13,905
Exercisable as of December 31, 2021		3,637,954		$	2.95		6.24	$	9,364
Vested and expected to vest as of December 31, 2021		7,608,158		$	4.81		7.68	$	13,896

Schedule of weighted-average assumptions

Risk-free interest rate:	1.61	%
Expected term (in years):	7.01
Expected volatility:	43.50	%
Dividend yield:	0.00	%

	2021			2020
Risk-free interest rate:		0.79	%		0.45	%
Expected term (in years):		6.05			6.13
Expected volatility:		42.10	%		37.25	%
Dividend yield:		0.00	%		0.00	%

	2021			2020
Risk-free interest rate:		1.39	%		0.59	%
Expected term (in years):		9.06			10
Expected volatility:		35.86	%		38.42	%
Dividend yield:		0.00	%		0.00	%

Schedule of stock-based compensation expense

	Three Months Ended March 31,
	2022		2021
Research and development	$	1,622	$	591
Sales and marketing		374		199
General and administrative		1,350		1,730
	$	3,347	$	2,520

	2021		2020
Research and development	$	4,001	$	941
Sales and marketing		1,185		387
General and administrative		6,159		8,177
	$	11,345	$	9,505

Restricted stock awards for employee bonus, net	2021		2020
Research and development	$	7,613	$	—
Sales and marketing		2,310		—
General and administrative		8,694		—
	$	18,617	$	—