PowerSync keeps backend SQL databases in sync with on-device SQLite databases embedded in a client SDK. It enables real-time reactive offline-first/local-first apps that remain available even when network connectivity is poor or non-existent. Offline-first / local-first is a paradigm where your app code works directly with a client-side embedded database, which automatically syncs with a backend database in the background. PowerSync currently supports Postgres with Flutter, React Native and web. Additional backend database support and SDKs are on the way.