Basis of presentation and summary of significant accounting policies (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) reportingUnit segment	Dec. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)	Jan. 01, 2022 USD ($)
Concentration Risk [Line Items]
Net income/(loss)	$ (7,700,000)	$ (12,599,000)	$ 10,807,000
Internally developed software, average useful life	2 years
Internally developed software, impairment	$ 0	0
Number of reporting units | reportingUnit	1
Employee contribute, percentage	90.00%
Restructuring expenses	$ 0	900,000
Defined contributions	0	0	0
Cash and cash equivalents	144,364,000	112,745,000
Foreign currency transaction gain (loss)	$ (700,000)	$ 300,000	$ (300,000)
Accounts Receivable | Customer Concentration Risk
Concentration Risk [Line Items]
Number of major customers | segment	1	3
Unbilled Receivables | Customer Concentration Risk
Concentration Risk [Line Items]
Number of major customers | segment	1	3
Sales | Customer Concentration Risk | Customer One
Concentration Risk [Line Items]
Concentration risk, percentage	11.60%	21.30%	23.10%
Sales | Customer Concentration Risk | Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%	11.80%	14.80%
Sales | Customer Concentration Risk | Customer Three
Concentration Risk [Line Items]
Concentration risk, percentage			13.00%
Russia
Concentration Risk [Line Items]
Cash and cash equivalents	$ 500,000	$ 700,000
Ukraine
Concentration Risk [Line Items]
Cash and cash equivalents	$ 600,000	200,000
Minimum
Concentration Risk [Line Items]
Property and equipment, useful life	2 years
Intangible assets, useful life	2 years
Minimum | Accounting Standards Update 2016-02 | Subsequent Event
Concentration Risk [Line Items]
Operating lease, right of use asset				$ 2,400,000
Operating lease liability				2,300,000
Maximum
Concentration Risk [Line Items]
Property and equipment, useful life	12 years
Intangible assets, useful life	12 years
Maximum | Accounting Standards Update 2016-02 | Subsequent Event
Concentration Risk [Line Items]
Operating lease, right of use asset				3,000,000
Operating lease liability				$ 2,900,000
Variable Interest Entity, Primary Beneficiary
Concentration Risk [Line Items]
Net income/(loss)	$ 600,000	$ 100,000	$ 100,000