Summary of significant accounting policies (Tables)

12 Months Ended

Dec. 31, 2022

Accounting Policies [Abstract]

Schedule of activity related to allowance for doubtful accounts

Activity related to our allowance for credit losses for trade accounts receivable was as follows:

	Years Ended December 31,
	2022		2021		2020
	(in thousands)
Balance, beginning of period	$	391	$	530	$	200
Provision	328		143		824
Write-offs	(321)		(373)		(494)
Recoveries of amounts previously written off	47		91		—
Balance, end of period	$	445	$	391	$	530

Schedule of stock-based payment award valuation inputs

The Company used the following assumptions in the Modified Black-Scholes option pricing model to estimate the fair value of return target options modified during the year ended December 31, 2020:

Expected life of options	1.5 years
Expected volatility	55%
Risk-free interest rates	0.16%
Expected dividend yield	—%
Weighted-average grant-date fair value	$8.95

Schedule of disaggregation of revenue

Revenue from subscription and non-subscription contractual arrangements were as follows:

	Years Ended December 31,
	2022		2021		2020
	(in thousands)
SaaS subscription and support and maintenance	$	430,613	$	313,950	$	223,655
On‑premise subscription	24,394		30,293		25,224
Subscription revenue	455,007		344,243		248,879
Professional services	19,025		16,122		14,519
Perpetual licenses	4,744		6,023		5,734
Non‑subscription revenue	23,769		22,145		20,253
Total revenue	$	478,776	$	366,388	$	269,132

Schedule of changes in contract assets and liabilities

The opening and closing balances of contract assets were as follows:

	Years Ended December 31,
	2022		2021		2020
	(in thousands)
Balance, beginning of the period	$	1,792	$	947	$	499
Balance, end of the period	817		1,792		947
Change	$	(975)	$	845	$	448

Changes in contract liabilities, including revenue earned during the period from the beginning contract liability balance and new deferrals of revenue during the period, were as follows:

	Years Ended December 31,
	2022		2021		2020
	(in thousands)
Balance, beginning of the period	$	282,128	$	205,509	$	140,449
Acquisitions	1,014		5,200		—
Revenue earned	(222,964)		(160,002)		(127,915)
Deferral of revenue	287,608		231,421		192,975
Other (1)	(1,636)		—		—
Balance, end of the period	$	346,150	$	282,128	$	205,509

(1) Includes contract assets netted against contract liabilities on a contract-by-contract basis.