Income taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Accruals and reserves	$ 4,409	$ 5,107
Deferred revenue	62,000	61,285
Net operating loss	36,508	30,047
Research and development tax credits	28,645	20,412
Stock-based compensation expense	6,242	7,995
Indirect tax reserves	240	1,496
Property and equipment, net	2,000	2,031
Capitalized research and development costs	35,505	23,475
Operating lease liabilities	1,460	2,767
Other	564	491
Gross deferred tax assets	177,573	155,106
Valuation allowance	(150,915)	(129,453)
Total deferred tax assets	26,658	25,653
Deferred tax liabilities:
Deferred contract costs	(16,791)	(14,814)
Operating lease right-of-use-assets	(1,129)	(2,245)
Other deferred tax liabilities	(8,573)	(8,594)
Total deferred tax liabilities	(26,493)	(25,653)
Net deferred tax assets	$ 165	$ 0