Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018
Operating activities
Net loss	$ (77,866)	$ (66,494)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	10,193	6,424
Amortization of intangible assets	285	373
Amortization of deferred contract acquisition costs	15,076	11,991
Change in fair value of redeemable convertible preferred stock warrant liability	6,022	2,055
Allowance for doubtful accounts	22	203
Stock-based compensation expense	33,611	3,943
Accretion of marketable securities purchased at a discount	(960)	(169)
Other	163	187
Changes in operating assets and liabilities
Accounts receivable	(22,802)	2,116
Deferred contract acquisition costs	(27,788)	(14,298)
Prepaid expenses and other assets	(12,505)	(91)
Accounts payable	(5,897)	(7,703)
Accrued expenses and other current liabilities	(2,095)	(9,058)
Accrued payroll and benefits	773	(1,647)
Deferred revenue	79,362	37,246
Other liabilities, noncurrent	(393)	(215)
Net cash used in operating activities	(4,799)	(35,137)
Investing activities
Purchases of property and equipment	(37,159)	(14,068)
Capitalized internal-use software	(3,310)	(3,201)
Purchases of marketable securities	(117,572)	(80,204)
Proceeds from sales of marketable securities	4,473
Maturities of marketable securities	123,314	2,600
Net cash used in investing activities	(30,254)	(94,873)
Financing activities
Proceeds from the issuance of common stock upon initial public offering, net of underwriting discounts	665,092
Proceeds from the issuance of redeemable convertible preferred stock, net of issuance costs		199,896
Repayment of loan payable		(6,158)
Proceeds from revolving line of credit		10,000
Repayment of revolving line of credit		(20,000)
Repayment of notes receivable from related parties		198
Payments of indemnity holdback		(500)
Repurchase of stock options		(2,330)
Payments of deferred offering costs	(4,080)
Proceeds from issuance of common stock upon exercise of stock options	8,526	1,514
Proceeds from the issuance of common stock upon exercise of early exercisable stock options	10,264
Net cash provided by financing activities	679,802	182,620
Effect of foreign exchange rates on cash and cash equivalents	(349)	(255)
Net increase in cash and cash equivalents	644,400	52,355
Cash and cash equivalents, beginning of period	88,408	63,179
Cash and cash equivalents, end of period	732,808	115,534
Supplemental disclosure of cash flow information:
Interest paid	2	448
Income taxes paid	413	432
Supplemental disclosure of non-cash investing and financing activities:
Indemnity holdback consideration associated with business combinations		1,799
Contingent consideration associated with business combinations		713
Conversion of redeemable convertible preferred stock to common stock	659,207
Conversion of redeemable convertible preferred stock warrant liabilities reclassed to additional paid-in capital	10,559
Net change in deferred offering costs, accrued but not paid	(1,078)
Net change in property and equipment included in accounts payable and accrued expenses	$ 3,820	$ 152