We currently have two employee equity plans that have been adopted by our board of directors. These plans, the 2015 Equity Incentive Plan (the "2015 Plan") and the 2015 Employee Stock Purchase Plan (the "2015 ESPP"), are described in more detail in Item 8. Financial Statements and Supplementary Data in our Form 10-K for the year ended January 31, 2023. As of April 30, 2023, 31,898,761 shares and 4,550,504 shares were reserved for future issuance under the 2015 Plan and the 2015 ESPP, respectively.

The following table summarizes the stock option activity under the equity incentive plans and related information:


	Shares Subject to Options Outstanding					Weighted- Average
				Weighted-		Remaining
				Average Exercise		Contractual Life		Aggregate
	Shares			Price		(Years)		Intrinsic Value
								(in thousands)
Balance as of January 31, 2023		2,373,063		$	17.32		3.81	$	34,820
Options exercised		(19,440	)		5.78
Options forfeited/cancelled		—			—
Balance as of April 30, 2023		2,353,623		$	17.41		3.59	$	21,331
Exercisable as of April 30, 2023		2,353,623		$	17.41		3.59	$	21,331

The following table summarizes the restricted stock unit activity under the equity incentive plans and related information:


	Number of			Weighted-
	Restricted			Average
	Stock Units			Grant Date
	Outstanding			Fair Value
Unvested balance - January 31, 2023		14,665,753		$	24.89
Granted		7,023,888			26.44
Vested		(2,225,935	)		23.83
Forfeited/cancelled		(208,799	)		24.92
Unvested balance - April 30, 2023		19,254,907		$	25.58

As of April 30, 2023, there was $465.1 million of unrecognized stock-based compensation expense related to outstanding restricted stock units granted to employees that is expected to be recognized over a weighted-average period of 2.93 years.

We use performance-based incentives for certain employees, including our named executive officers, to achieve our annual financial and operational objectives, while making progress towards our longer-term strategic and growth goals. Based on a review of our actual achievement of the pre-established corporate financial objectives and additional inputs from our Compensation Committee, the executive bonus plan for fiscal year 2023 was determined, settled and paid out in the first quarter of fiscal year 2024 in the form of cash and fully vested restricted stock units. During the first quarter of fiscal year 2024, our Compensation Committee also adopted and approved the performance criteria and targets for the executive bonus plan for fiscal year 2024, which is expected to be paid out in the form of cash and fully vested restricted stock units in the first quarter of fiscal year 2025.

During the three months ended April 30, 2023 we recognized stock-based compensation expense related to executive bonus plans in the amount of $3.2 million. The unrecognized compensation expense related to the ungranted and unvested executive bonus plan for fiscal year 2024 is $10.7 million, based on the expected performance against the pre-established corporate financial objectives as of April 30, 2023, which is expected to be recognized over a remaining weighted-average period of less than one year.

As of April 30, 2023, there was $17.2 million of unrecognized stock-based compensation expense related to the 2015 ESPP that is expected to be recognized over the remaining term of the respective offering periods.

The following table summarizes the components of stock-based compensation expense recognized in the condensed consolidated statements of operations (in thousands):


	Three Months Ended
	April 30,
	2023		2022
Cost of revenue	$	4,485	$	4,355
Research and development		17,002		17,726
Sales and marketing		15,318		15,289
General and administrative		10,472		9,740
Total stock-based compensation	$	47,277	$	47,110