For backend we're working on a starter kit that puts together all the pieces (there are a lot!) that's days from release, if you reach out on the Discord I can help get you on as a beta tester. It uses Supabase for data and auth, which seems to give the best overall package for data and auth.

For state depends entirely on the complexity of app. For simple apps you can get away with just something like React Query and Reacts useState, for more complex one of Daishi's state management libraries (everyone has their different preference, I love the black sheep Valtio), or the new kid on the block Legend State looks interesting.

The biggest part is getting a monorepo set up properly with shared code. Again the Tamagui starter repo `npm create tamagui` has this set up and its a whole ton of work saved in terms of getting that right.