I've wasted a lot of time during my attempts as a solo developer to build a product with a scalable backend architecture for the hordes of users that never mate

I've wasted a lot of time during my attempts as a solo developer to build a product with a scalable backend architecture for the hordes of users that never materialize. Next idea I have, I swear I'm going to throw all my effort into the frontend and go with as minimal a backend as I can get away with (heck, depending on the application, human-in-the-loop might be fine early on) until I get some validation. It'll feel "wrong", but whatever.