Stock-based compensation - Stock Options - (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2024
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning balance (in shares)	7,425,444
Granted (in shares)	2,325,226
Exercised (in shares)	(86,100)
Cancelled or forfeited (in shares)	(793,242)
Outstanding, ending balance (in shares)	8,871,328
Exercisable (in shares)	4,604,321
Weighted Average Exercise Price
Outstanding (in dollars per share)	$ 8.52
Granted (in dollars per share)	7.79
Exercised (in dollars per share)	4.11
Cancelled or forfeited (in dollars per share)	11.69
Outstanding (in dollars per share)	8.08
Exercisable (in dollars per share)	$ 8.51
Remaining Contractual Life
Outstanding	7 years 6 months
Exercisable	6 years 4 months 24 days
Aggregate Intrinsic Value
Outstanding	$ 3,756
Exercisable	2,777
Employee Stock Option [Member]
Options disclosures
Unrecognized stock-based compensation expense	$ 20,100
Remaining weighted-average remaining vesting period	2 years 8 months 12 days