Speed comes from saying no to the right things. These choices keep the first version small without making it throwaway.
One platform or one user type first
We start where your users are, and add the second platform or role once the first one proves its value.
Managed services over custom builds
Authentication, payments, email and push notifications use proven services, so build time goes into what makes your product different.
Manual work behind the scenes
Some processes, such as approvals or matching, can be done by hand in the admin panel until volume justifies automation.
Nice-to-have features
Anything that does not test the core idea goes on a backlog ranked by user feedback after launch.