Firenook is a Rust-based drop-in replacement for the Firebase Local Emulator Suite that keeps the same ports, SDK behavior and import/export format but runs without Java and with persistent on-disk state. It advertises much better performance — e.g. ~40× faster writes, ~10× lower memory usage and far quicker restarts — while emulating Firestore, Auth, Storage, Functions, Pub/Sub and the emulator console.