WebAssembly is still mostly a “use it when you actually need it” thing, and this piece walks through the usual Rust/Emscripten setup, where the speed wins show up, and where Wasm still gets kind of annoying in real web apps.
Wasm speed is real, but the part that keeps biting me is the JS↔Wasm boundary. You get the wins when you can hand over one big, boring chunk of work, keep the data in linear memory, and not ping-pong across the boundary 1,000 times; once you’re copying buffers or trying to “pass objects,” the overhead shows up immediately.
Kirupa has a good write-up on interop/data passing that made this finally click for me.
