While it is true that everything CAN be outsourced, not everything SHOULD be outsourced. Generally, anything that is not your core competency is a good candidat

While it is true that everything CAN be outsourced, not everything SHOULD be outsourced. Generally, anything that is not your core competency is a good candidate for outsourcing. So your example of payroll processing is a good idea to outsource, but I wouldn't outsource the main product of the startup (like don't outsource building the tech if that is your product). Outsource legal, backoffice, HR, etc.