Open‑source Backend‑as‑a‑Service (BaaS) with database, auth, storage, and functions. Self‑hostable, with a cloud free tier. Great for modern web and mobile apps.
Appwrite is a comprehensive open‑source BaaS with database, auth, storage, functions, and realtime APIs. Self‑host or use the cloud version (free tier available).
I built a task management app backend with Appwrite cloud. Created collections, configured permissions, and added auth via the admin UI. The SDK integration was smooth, and the free tier (25K MAU) was more than enough.
Appwrite is one of the best open‑source Firebase alternatives, with great docs and feature set.
Pro tip: Appwrite’s cloud functions can be triggered on events (e.g., send welcome email after signup). Free tier includes 50K function invocations/month.