[sofixa]

> n my personal opinion, always optimise for user experience

If you have unlimited money, that is. If you don't, a suboptimal UX is better than no UX.

> Shared code should be in the backend, not in your mobile app. Your mobile app (ignoring camera filters & games, as they should use an engine; unity etc) should just be a JSON viewer, with a small bit of data entry. Anything else is over-engineering, generally.

Ideally, yes, but depending on the app the frontend can still be heavy - e.g. with Coinbase, all the graphing and real-time stuff, done 3 times over, are probably a not insignificant effort.