What a timely question! A couple of friends and I have been wrestling with the question, and coming from the enterprise world, have been retooling for producing code over producing production code for the MVP. We currently are looking working with

* Flutter, with FlutterFlow for UI * Pocketbase for quick, extendable back end code and basic BaaS * Heavier emphasis on market validation and strategy than technology

We set a goal that the MVP is barely a mock-up. The other understanding we have is that the backend would have to be 100% rebuilt if / when there is traction, but we were able to get to work in one web meeting.