Calling Rust from Node.js: A Practical Guide to NAPI-RS

Note: I used Claude to write this whole article based on my github and youtube video linked at the end. You have a Node.js backend. Somewhere in it, there's a hot path — maybe image processing, maybe a parser, maybe a prime-checker for some cursed reason — and you'd like it to be faster. You've heard Rust is fast. But you don't want to rewrite your whole backend in Rust, and you really don't want to spin up a separate Rust web server just to expose one function over HTTP. Enter NAPI-RS : a frame