Fair Value of Financial Instruments - Schedule of Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Jul. 31, 2025	Jan. 31, 2025
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Amortized Cost	$ 322,702	$ 186,331
Cash and cash equivalents, Estimated Fair Value	322,702	186,331
Cash and cash equivalents and available for sale securities, Amortized Cost	1,523,921	704,765
Gross Unrealized Gains	161	548
Gross Unrealized Losses	(1,071)	(169)
Cash and cash equivalents and short term investments, Estimated Fair Value	1,523,011	705,144
Short-term investments, estimated fair value	1,200,309	518,813
Cash
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Amortized Cost	72,680	75,541
Cash and cash equivalents, Estimated Fair Value	72,680	75,541
Level 1:
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Estimated Fair Value	234,124	96,423
Cash and cash equivalents and available for sale securities, Amortized Cost	718,470	355,750
Gross Unrealized Gains	41	345
Gross Unrealized Losses	(361)	(76)
Cash and cash equivalents and short term investments, Estimated Fair Value	718,150	356,019
Short-term investments, estimated fair value	484,026	259,596
Level 1: | U.S. Treasuries
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Estimated Fair Value	59,797	0
Cash and cash equivalents and available for sale securities, Amortized Cost	544,143	259,327
Gross Unrealized Gains	41	345
Gross Unrealized Losses	(361)	(76)
Cash and cash equivalents and short term investments, Estimated Fair Value	543,823	259,596
Short-term investments, estimated fair value	484,026	259,596
Level 1: | Money market funds
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Amortized Cost	174,327	96,423
Cash and cash equivalents, Estimated Fair Value	174,327	96,423
Level 2:
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Estimated Fair Value	15,898	14,367
Cash and cash equivalents and available for sale securities, Amortized Cost	732,771	273,474
Gross Unrealized Gains	120	203
Gross Unrealized Losses	(710)	(93)
Cash and cash equivalents and short term investments, Estimated Fair Value	732,181	273,584
Short-term investments, estimated fair value	716,283	259,217
Level 2: | Certificate of deposit
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents and available for sale securities, Amortized Cost	7,631
Gross Unrealized Gains	12
Gross Unrealized Losses	0
Cash and cash equivalents and short term investments, Estimated Fair Value	7,643
Short-term investments, estimated fair value	7,643
Level 2: | Commercial paper
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Estimated Fair Value		14,367
Cash and cash equivalents and available for sale securities, Amortized Cost	33,280	88,732
Gross Unrealized Gains	0	8
Gross Unrealized Losses	(61)	(3)
Cash and cash equivalents and short term investments, Estimated Fair Value	33,219	88,737
Short-term investments, estimated fair value	33,219	74,370
Level 2: | Corporate bonds
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Estimated Fair Value	15,898	0
Cash and cash equivalents and available for sale securities, Amortized Cost	685,970	184,742
Gross Unrealized Gains	108	195
Gross Unrealized Losses	(640)	(90)
Cash and cash equivalents and short term investments, Estimated Fair Value	685,438	184,847
Short-term investments, estimated fair value	669,540	$ 184,847
Level 2: | U.S. government agencies
Debt Securities, Available-for-Sale [Line Items]
Cash and cash equivalents, Estimated Fair Value	0
Cash and cash equivalents and available for sale securities, Amortized Cost	5,890
Gross Unrealized Gains	0
Gross Unrealized Losses	(9)
Cash and cash equivalents and short term investments, Estimated Fair Value	5,881
Short-term investments, estimated fair value	$ 5,881