Yes, you heard that correctly. The router state is written to SQLite by Rust.
I'm copying a pattern used by Facebook Messenger where all UI state is stored in SQLite and the UI is a thin, pure function render:
- https://engineering.fb.com/data-infrastructure/messenger/
- https://www.droidcon.com/2019/10/25/the-light-way-2/
In the demo I can kill the app and re-open it in exactly the same place because the router state is stored in SQLite.
Discussion
SwiftUI re-renders reactively based on changes in this view model, which just receives notifications of any relevant changes to the SQLite database 
This is how the database changes are propogated to Swift. sqlite-watcher listens for changes to database tables in Rust, and sends notifications to Swift via Updater::send_update 
Strict 1-directional data flow as God intended 
Beautifully simple
You write your UI in platform-native options like SwiftUI or Jetpack Compose. You could also write it in React Native or Flutter. But honestly I don't think they are worth it. When the UI is a pure function you can vibe-code it. Your application is written and tested in Rust.
The UI above was a Cursor one-shot based on this TLDraw diagram. Notice how it put the "choose mint" screen in the wrong place. History screen was also broken so commented it out.
Forget React Native and Flutter!
Why SQLite and not a rust native data store like redb ?
Because SQLite is so stable and well-supported. Should I look into redb? Does anything use it in production? Last time I looked it was only Casey Rodarmor using it lol.
For sure its not as battle tested as sqlite but Im playing around with it since its interesting tech. Rodarmor is looking at making a bdk wallet persister with it too.
