A fitness trainer platform with millions of users: every trainer gets their own app in the stores. When I joined it was a monorepo with a hundred branches, where every build was a manual operation.
I replaced it with a modular “skeleton + skin” system and a semi-automated build pipeline. A release went from several days to two hours, and the app count passed 400.
The full write-up is still being written — this is the short version for now. Happy to walk you through the details.