Rust + WebAssembly

Run near-native Rust in the browser. WASM wins for compute-heavy, long-running work — not for DOM-bound or trivial tasks where the JS↔WASM boundary cost dominates.

When WASM is worth it

• ✅ Heavy number crunching: image/audio/video processing, physics, simulation, compression, crypto, parsers, geometry.
• ✅ Workloads that run for milliseconds+ per call and touch large typed-array buffers.
• ✅ Code you want to share with a native/Rust backend.
• ❌ Small/occasional ops where boundary marshaling > the compute saved.
• ❌ DOM-heavy logic (WASM can't touch the DOM directly; it calls back into JS).

Rule of thumb: fewer, bigger calls beat many tiny calls.

Toolchain

rustup target add wasm32-unknown-unknown
cargo install wasm-pack       # bundles wasm + JS glue + TS types