CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net loss	$ (43,037)	$ (16,237)	$ (12,723)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	5,565	867	770
Depreciation expense	1,443	640	398
Non-cash operating lease expense	1,624
Other non-cash items	52	7	(45)
Changes in operating assets and liabilities:
Accounts receivable	(3,619)	(4,991)
Prepaid expenses and other current assets	(6,005)	(7,049)	(67)
Other non-current assets	869	(1,465)	(83)
Accounts payable	4,203	3,413	(1,172)
Deferred revenues	(4,442)	8,587
Operating lease liabilities	(2,396)
Accrued expenses and other liabilities	4,012	1,230	1,009
Net cash used in operating activities	(41,731)	(14,998)	(11,913)
Investing activities:
Purchases of property and equipment	(1,999)	(2,150)	(1,297)
Net cash used in investing activities	(1,999)	(2,150)	(1,297)
Financing activities:
Payments related to finance leases	(1,437)
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs	37,274	6,439	58,145
Proceeds from issuance of common stock, net of issuance costs	74,756	9
Proceeds from borrowings		425	747
Repayments of borrowings	(842)	0
Net cash provided by financing activities	109,751	6,873	58,892
Net increase (decrease) in cash, cash equivalents and restricted cash	66,021	(10,275)	45,682
Cash, cash equivalents and restricted cash at beginning of period	48,580	61,362	13,186
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(1,026)	(2,507)	2,494
Cash, cash equivalents and restricted cash at end of period	113,575	48,580	61,362
Supplemental disclosure of cash flow information:
Cash paid for interest	(64)	(71)	(60)
Cash paid for income taxes		(24)	(4)
Supplemental disclosure of non-cash financing activities:
Due from shareholder for issuance of redeemable convertible preferred stock			6,520
Conversion of redeemable preferred shares upon the IPO	142,048
Property and equipment additions in accounts payable and accrued expenses	$ (10)	$ 545	$ (533)