tl;dr: A student built WATaBoy, a Game Boy emulator that JIT-compiles SM83 instructions to WebAssembly bytecode, relying on the browser's JS engine to further compile the Wasm to native machine code—a workaround for iOS's JIT restrictions. Benchmarks show the JIT-to-Wasm approach runs ~1.2x faster than a native interpreter and ~1.5x faster than a Wasm interpreter, with Safari outperforming Chrome and Firefox. The post also walks through Wasm codegen, linking, and indirect dispatch from Rust, and argues this technique could enable faster cross-platform emulation if codegen tooling matures.