CASH AND CASH EQUIVALENTS, INVESTMENTS, AND FAIR VALUE MEASUREMENTS - Schedule of Fair Value, Assets Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Oct. 31, 2025	Jan. 31, 2025
Cash and cash equivalents:
Amortized Cost	$ 150,206	$ 186,574
Short-term investments:
Amortized Cost	498,283	534,391
Gross Unrealized Gains	1,406	1,022
Gross Unrealized Losses	(49)	(82)
Estimated Fair Value	499,640	535,331
Long-term investments:
Amortized Cost	192,336	395,444
Gross Unrealized Gains	884	1,360
Gross Unrealized Losses	0	(597)
Estimated Fair Value	193,220	396,207
Total assets measured at fair value, Amortized Cost	840,825	1,116,408
Total assets measured at fair value, Gross Unrealized Gains	2,290	2,385
Total assets measured at fair value, Gross Unrealized Losses	(49)	(681)
Total assets measured at fair value, Estimated Fair Value	843,066	1,118,112
Cash
Cash and cash equivalents:
Amortized Cost	106,456
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Estimated Fair Value	106,456
Total cash and cash equivalents
Cash and cash equivalents:
Amortized Cost	150,206	186,573
Gross Unrealized Gains	0	3
Gross Unrealized Losses	0	(2)
Estimated Fair Value	150,206	186,574
Level 1 | U.S. treasury securities
Short-term investments:
Amortized Cost	291,123	208,918
Gross Unrealized Gains	853	284
Gross Unrealized Losses	(5)	(74)
Estimated Fair Value	291,971	209,128
Long-term investments:
Amortized Cost	93,748	208,104
Gross Unrealized Gains	445	787
Gross Unrealized Losses	0	(203)
Estimated Fair Value	94,193	208,688
Level 1 | Cash
Cash and cash equivalents:
Amortized Cost		94,728
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Estimated Fair Value		94,728
Level 1 | Money market funds
Cash and cash equivalents:
Amortized Cost	43,750	61,962
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	43,750	61,962
Level 2 | Commercial paper
Short-term investments:
Amortized Cost		24,606
Gross Unrealized Gains		1
Gross Unrealized Losses		(2)
Estimated Fair Value		24,605
Level 2 | Corporate notes and bonds
Short-term investments:
Amortized Cost	198,660	238,610
Gross Unrealized Gains	553	586
Gross Unrealized Losses	(35)	(6)
Estimated Fair Value	199,178	239,190
Long-term investments:
Amortized Cost	98,588	173,882
Gross Unrealized Gains	439	573
Gross Unrealized Losses	0	(331)
Estimated Fair Value	99,027	174,124
Level 2 | U.S. agency securities
Short-term investments:
Amortized Cost	8,500	62,257
Gross Unrealized Gains	0	151
Gross Unrealized Losses	(9)	0
Estimated Fair Value	$ 8,491	62,408
Long-term investments:
Amortized Cost		13,458
Gross Unrealized Gains		0
Gross Unrealized Losses		(63)
Estimated Fair Value		13,395
Level 2 | U.S. treasury securities
Cash and cash equivalents:
Amortized Cost		9,969
Gross Unrealized Gains		3
Gross Unrealized Losses		0
Estimated Fair Value		9,972
Level 2 | Commercial paper
Cash and cash equivalents:
Amortized Cost		19,914
Gross Unrealized Gains		0
Gross Unrealized Losses		(2)
Estimated Fair Value		$ 19,912