The Abstract Wikipedia team is working toward a rewrite of our backend services in a different programming language, likely Rust. Node/JS has served us well, but we have run up against some [WebAssembly System Interface] limits that would be best dealt with by switching to a different ecosystem.
Node.js is a runtime, you can compile a number of languages to it. It’s useful because it can have relatively low resource usage and there are a lot of libraries available for it.