I purposely did not set up any infrastructure for my iOS app Reflect and made it local-first [0]. I did it so that I could make the app completely private but it’s come with the wonderful side effect that the product is easily horizontally scalable. The only overhead I have for more users is a busier discord channel and so far that community growth has felt very rewarding.
[0] https://apps.apple.com/us/app/reflect-track-anything/id64638...