Convex

Convex is a backend platform built around a real-time database with a TypeScript-first developer experience. Server functions and queries are written in TypeScript, and clients subscribe to their results, so state changes propagate without a hand-built sync layer. It sits in the gap between a database and a backend: the subscriptions, consistency and reactive plumbing most teams end up reimplementing, badly, for every application.

We track it rather than run it. We list it as the option for products where live shared state is the feature rather than a nicety — collaborative editing, multiplayer views, agent runs streaming into a UI.

Supabase is the closest practical comparison and the safer default: Postgres underneath, realtime available, and you can take the database with you. Firebase for the same reactive model with a longer track record and the Google ecosystem attached. Neon or PlanetScale when you want plain managed SQL and will write the backend yourself. Appwrite if open source and self-hosting matter more than developer experience. Convex is the wrong call when you need ordinary SQL, heavy analytical querying, or portability — a Postgres you can move is worth more than a nicer API there. It is the right call when the reactive model genuinely matches the product.