Equity Incentive Plans - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Oct. 31, 2020 USD ($) $ / shares shares	Apr. 30, 2020 USD ($) $ / shares shares
Number of Stock Options Outstanding
Balance as of April 30, 2020 (in shares) | shares	15,260,506
Stock options granted (in shares) | shares	40,129
Stock options exercised (in shares) | shares	(4,035,115)
Stock options cancelled (in shares) | shares	(506,718)
Stock options assumed in acquisition cancelled (in shares) | shares	(899)
Balance as of October 31, 2020 (in shares) | shares	10,757,903	15,260,506
Exercisable as of October 31, 2020 (in shares) | shares	5,926,542
Weighted- Average Exercise Price
Balance as of April 30, 2020 (in dollars per share) | $ / shares	$ 14.17
Stock options granted (in dollars per share) | $ / shares	99.78
Stock options exercised (in dollars per share) | $ / shares	11.25
Stock options cancelled (in dollars per share) | $ / shares	19.19
Stock options assumed in acquisition cancelled (in dollars per share) | $ / shares	75.00
Balance as of October, 2020 (in dollars per share) | $ / shares	15.33	$ 14.17
Exercisable as of October 31, 2020 (in dollars per share) | $ / shares	$ 12.36
Remaining Contractual Term (in years)
Remaining contract term	6 years 11 months 4 days	7 years 3 months 7 days
Exercisable, remaining contractual term	6 years 6 months 21 days
Aggregate Intrinsic Value
Balance as of April 30, 2020 | $	$ 767,795
Balance as of October 31, 2020 | $	925,989	$ 767,795
Exercisable as of October 31, 2020 | $	$ 527,662