Prototype to production involves determining the flaws in usability and scalability, deployment, build, testing, etc. You don’t want to crowbar your prototype into a live environment and then find yourself in a position where you need to upgrade but can’t. So, plan out what the development and release cycle looks like. Load test the backend, understand what load it can cope with vs. what you expect, and make changes if necessary.

Also, think about it from a security perspective. You’ve been testing with “friendly” users until now when the rest of the world can get access; how secure is your application from attack?