Calculate the net pay etc. while being compliant with federal/state regulations only, or automate payments to employee accounts as well? What is the minimal value that such saas can provide to get massive number of users?
https://www.federalreserve.gov/paymentsystems/fednow_about.h...
Payments also offers the perfect monetization option --- charge for each transfer.
Automated payments may not be necessary.
With the new FedNow service, some banks are offering cash managment software that allows direct transfer to employee accounts. A payroll system may only need to interface with these.