CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Revenue	$ 200,462	$ 144,563	$ 104,900
Cost of revenue	88,322	65,499	48,672
Gross profit	112,140	79,064	56,228
Operating expenses:
Research and development	46,492	34,618	28,989
Sales and marketing	71,097	50,134	40,818
General and administrative	41,099	23,450	17,451
Total operating expenses	158,688	108,202	87,258
Loss from operations	(46,548)	(29,138)	(31,030)
Interest income	3,287	939	443
Interest expense	(5,236)	(1,810)	(1,116)
Other income (expense), net	(2,561)	(741)	(539)
Loss before income taxes	(51,058)	(30,750)	(32,242)
Income taxes	492	185	208
Net loss	$ (51,550)	$ (30,935)	$ (32,450)
Net loss per share attributable to common stockholders, basic and diluted (USD per share)	$ (0.75)	$ (1.27)	$ (1.39)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	68,350	24,376	23,402