Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016
Cash flows from operating activities
Net loss	$ (35,082)	$ (30,999)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	5,557	3,265
Amortization of deferred commissions	2,967	2,976
Stock-based compensation	20,783	5,649
Other non-cash items	202	606
Changes in operating assets and liabilities net of effects from acquisitions:
Accounts receivable	15,625	3,773
Prepaid expenses and other current assets	(571)	(5,483)
Other assets	503	(944)
Deferred commissions	(2,915)	(2,623)
Accounts payable	335	202
Accrued expenses and other liabilities	8,408	4,963
Deferred revenue	5,703	8,071
Net cash provided by (used in) operating activities	21,515	(10,544)
Cash flows from investing activities
Acquisitions, net of cash acquired	(39,593)
Purchase of property and equipment	(3,587)	(3,500)
Increase in restricted cash	34
Net cash used in investing activities	(43,146)	(3,500)
Cash flows from financing activities
Proceeds from issuance of common stock, net of underwriting discounts, commissions and offering costs	22,264	138,189
Proceeds from the exercise of common stock options	10,120	4,100
Excess tax benefit from stock-based compensation		52
Proceeds from issuance of common stock for employee stock purchase plan	6,824
Net cash provided by financing activities	39,208	142,341
Net increase in cash and cash equivalents	17,577	128,297
Cash and cash equivalents at beginning of period	201,721	92,348
Cash and cash equivalents at end of period	219,298	220,645
Supplemental disclosure of cash flow data
Cash paid for income taxes	632	118
Supplemental disclosure of non-cash investing and financing activities
Vesting of early exercised stock options	2,128	389
Property and equipment included in accounts payable and accrued expenses and other current liabilities	$ 72	121
Conversion of convertible preferred stock to common stock		164,950
Offering costs included in accounts payable and accrued expenses and other current liabilities		$ 974