Stock-based compensation - Stock Options - (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning balance (in shares) | shares	6,199,571
Granted (in shares) | shares	2,250,400
Exercised (in shares) | shares	(377,593)
Cancelled or forfeited (in shares) | shares	(326,785)
Outstanding, ending balance (in shares) | shares	7,745,593	6,199,571
Exercisable (in shares) | shares	3,527,536
Weighted Average Exercise Price
Outstanding (in dollars per share) | $ / shares	$ 8.12
Granted (in dollars per share) | $ / shares	8.64
Exercised (in dollars per share) | $ / shares	5.02
Cancelled or forfeited (in dollars per share) | $ / shares	9.60
Outstanding (in dollars per share) | $ / shares	8.42	$ 8.12
Exercisable (in dollars per share) | $ / shares	$ 9.66
Remaining Contractual Life
Outstanding	7 years 10 months 24 days	7 years 10 months 24 days
Exercisable	6 years 8 months 12 days
Aggregate Intrinsic Value
Outstanding | $	$ 9,348	$ 6,095
Exercisable | $	4,355
Stock options
Options disclosures
Unrecognized stock-based compensation expense | $	$ 19,100
Remaining weighted-average remaining vesting period	2 years 10 months 24 days