Summary of significant accounting policies (Tables)

6 Months Ended

Jun. 30, 2021

Accounting Policies [Abstract]

Disaggregation of Revenue

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

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020 (1)		2021 (2)		2020 (1)
			(As Revised)				(As Revised)
	(in thousands)
SaaS subscription and support and maintenance	$	72,121	$	52,830	$	138,897	$	102,494
On‑premise subscription	8,597		5,770		16,303		10,310
Subscription revenue	80,718		58,600		155,200		112,804
Professional services	3,929		2,632		7,932		6,719
Perpetual licenses	1,591		1,032		3,833		2,794
Non‑subscription revenue	5,520		3,664		11,765		9,513
Total revenue	$	86,238	$	62,264	$	166,965	$	122,317

(1) Certain prior period amounts have been revised to correct immaterial errors. See Note 1 for more information.

(2) Includes the three months ended March 31, 2021, which has been revised to correct immaterial errors. See Note 1 for more information.

Contract with Customer Asset and Liability

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:

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020 (1)		2021 (2)		2020 (1)
			(As Revised)				(As Revised)
	(in thousands)
Balance, beginning of the period	$	221,579	$	145,312	$	205,509	$	140,449
Revenue earned	(66,967)		(49,393)		(111,398)		(91,395)
Deferral of revenue	83,845		61,363		144,346		108,228
Balance, end of the period	$	238,457	$	157,282	$	238,457	$	157,282

(1) Certain prior period amounts have been revised to correct immaterial errors. See Note 1 for more information.

(2) Includes the three months ended March 31, 2021, which has been revised to correct immaterial errors. See Note 1 for more information.