Income taxes - Components of the company's current and deferred tax assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Operating loss carryforwards	$ 45,452	$ 30,536
Research credit carryforwards		1,862
Operating lease liability	3,566	3,626
Share-based compensation	9,842	4,406
Capitalized research and development expenses	5,168
Accrued expenses and other	2,318	1,496
Total deferred tax assets	66,346	41,926
Deferred tax liabilities:
Operating lease right-of-use asset	(3,474)	(3,665)
Depreciation & amortization	(933)	(439)
Total deferred tax liabilities	(4,407)	(4,104)
Valuation allowance	(53,743)	(34,601)
Net deferred tax assets	$ 8,196	$ 3,221