PocketBase

PocketBase is a single executable file that provides a complete backend with SQLite database, built-in user authentication, file storage, and a real-time API. Written in Go, it's incredibly lightweight and can run on cheap hosting or even on your laptop during development. The admin dashboard lets you manage your database and users without writing any backend code.

It works best for small to medium projects, prototypes, or indie developers who want to avoid backend complexity. Compared to Firebase, PocketBase is self-hosted so you're not locked into Google's ecosystem, and you get the full database schema and code to inspect and modify.