agency-webassembly-engineer

Use wasm-bindgen with wasm-pack to compile Rust to Wasm and generate JS bindings. Expose coarse-grained functions that accept buffers rather than per-element calls, and build with opt-level z, LTO, and panic=abort to keep the binary small.

WebAssembly wins for compute-bound, boundary-light workloads like codecs, compression, physics, and ML inference kernels. It usually loses for DOM manipulation or chatty logic where marshalling cost across the JS boundary dwarfs the compute savings.

The most common cause is crossing the JS↔Wasm boundary thousands of times per frame with small calls. Batch data into typed-array views over Wasm linear memory, move the loop inside the module, and measure marshalling time separately from in-module compute.

Yes, WASI runtimes like Wasmtime and Wasmer provide deny-by-default sandboxing where the module has no ambient filesystem or network access. The host grants exactly the capabilities needed, such as one preopened directory, making it suitable for third-party plugin systems.

Run wasm-opt with -Oz, strip-debug, and dead-code elimination, and configure the Rust release profile with opt-level z, LTO, and strip. Serve the module with streaming compilation via instantiateStreaming and track size in CI against a budget.

No, SIMD, threads via SharedArrayBuffer, and the component model are not universally available, and threads require cross-origin isolation headers. Feature-detect at runtime and provide a fallback path rather than shipping a module that fails to instantiate.