CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net loss	$ (11,990)	$ (9,727)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,715	3,738
Amortization of deferred rent	204	17
Amortization of debt issuance costs	19	159
Stock-based compensation	6,329	1,467
Provision for doubtful accounts	150	602
Change in fair value of preferred stock warrant liabilities	0	706
Other adjustments	(39)	(224)
Interest paid on capital leases	(119)	(77)
Loss on disposals of property and equipment	0	36
Changes in operating assets and liabilities:
Accounts receivable	(6,031)	(4,586)
Prepaid expenses and other current assets	(1,148)	(931)
Other assets	(1,400)	(1,860)
Accounts payable	3,112	1,686
Accrued expenses	(1,495)	(507)
Other liabilities	507	(582)
Net cash used in operating activities	(7,186)	(10,083)
Cash flows from investing activities:
Purchases of marketable securities	0	(20,088)
Sales of marketable securities	0	3,578
Maturities of marketable securities	21,400	17,700
Purchases of property and equipment	(10,221)	(4,025)
Capitalized internal-use software	(1,437)	(759)
Net cash provided by (used in) investing activities	9,742	(3,594)
Cash flows from financing activities:
Repayments of notes payable	0	(2,488)
Repayments of capital leases	(1,541)	(336)
Proceeds from employee stock purchase plan	2,133	0
Proceeds from exercise of vested stock options	3,174	639
Proceeds from early exercise of stock options	0	250
Proceeds from payment of stockholder note	0	12
Net cash provided by (used in) financing activities	3,766	(1,923)
Effects of exchange rate changes on cash, cash equivalents, and restricted cash	37	(8)
Net increase in cash, cash equivalents, and restricted cash	6,359	(15,608)
Cash, cash equivalents, and restricted cash at beginning of period	86,229	36,963
Cash, cash equivalents, and restricted cash at end of period	92,588	21,355
Supplemental disclosure of cash flow information:
Cash paid for interest	155	1,446
Cash paid for income taxes, net of refunds received	814	2
Property and equipment additions not yet paid in cash	5,628	32
Vesting of early-exercised stock options	146	155
Capital lease outstanding from current year addition	3,226	4,082
Stock-based compensation capitalized to internal-use software	248	0
Reconciliation of cash, cash equivalents, and restricted cash as shown in the statements of cash flows
Total cash, cash equivalents, and restricted cash	$ 92,588	$ 21,355