Stockholders' Equity and Stock-based Compensation Expense (Tables)

9 Months Ended

Sep. 30, 2021

Share-based Payment Arrangement [Abstract]

Summary of Activity under the 2019 Plan

Activity under the Company's equity incentive plans is summarized as follows:

	Shares Available for Grant
Balance, December 31, 2020	1,085,170
Additional shares reserved	450,000
RSUs granted	(213,522)
PSUs granted	(463,593)
Options granted	(172,139)
Stock awards canceled / forfeited / expired	295,392
Options canceled / forfeited / expired	24,090
Balance, September 30, 2021	1,005,398

	Options Outstanding
	Number of Stock Options Outstanding	Weighted- Average Exercise Price		Weighted Average Remaining Term  (in Years)
Balance, December 31, 2020	217,007	$	22.35	3.75
Options granted	172,139	$	30.71
Options exercised	(57,498)	$	24.49
Options canceled / forfeited / expired	(24,090)	$	32.90
Balance, September 30, 2021	307,558	$	25.80	4.84

	Stock Awards Outstanding
	Number of Awards Outstanding	Weighted Average Grant Date Fair Value per Share
Balance, December 31, 2020	779,757	$	23.96
RSUs granted	213,522	$	36.80
PSUs granted	463,593	$	41.23
Awards released	(175,813)	$	22.45
Stock awards canceled / forfeited / expired	(298,028)	$	27.24
Balance, September 30, 2021	983,031	$	33.91

Summary of Stock-based Compensation Expense

Stock-based compensation expense by department recognized during the three and nine months ended September 30, 2021 and 2020 was as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Cost of revenue	$	330	$	326	$	908	$	1,359
Sales and marketing	711		648		1,954		2,618
Research and development	1,020		254		1,628		1,344
General and administrative	1,681		754		4,017		2,736
Total stock-based compensation expense	$	3,742	$	1,982	$	8,507	$	8,057