A practical note for developers who want to build across desktop and mobile without rewriting the same business logic for every platform. SwarmNote uses Tauri + React on desktop, Expo + React Native on mobile, and one shared Rust core underneath. SwarmNote: Your notes, swarming across your own devices. The Short Version SwarmNote’s cross-platform architecture is not “one desktop app, one mobile app, and a lot of duplicated business logic.” It is split into three layers: Product UI layer : React + Tauri WebView on desktop, Expo + React Native on mobile. Platform adapter layer : desktop exposes Rust through #[tauri::command] ; mobile exposes Rust through uniffi-bindgen-react-native and a JSI/Turbo Module. Shared core layer : swarmnote-core , a platform-independent Rust crate that owns workspaces, documents, Yjs/yrs state, pairing, and P2P sync. In other words, desktop and mobile are not two separate products. They are two different shells around the same Rust core.…