Just go to its repo https://github.com/uNetworking/uWebSockets.js and see the uWebSockets submodule dependency that it's written in C++ (90.9%) and C (6.8%)...so sure, a "fair" comparison indeed with vanilla implementation!
Ok...Node is itself written in C++. The V8 and JavaScriptCore JS engines have no concept of a server (they were designed for web browsers), so under the hood JS runtimes implement servers in a lower level language capable of interfacing with Linux syscalls. Bun uses Zig, Deno uses Rust, Node uses C++, etc. I don't think that necessarily makes this an unfair comparison. The database drivers used in these benchmarks are also usually written in C++. Look at the repo for the native Postgres binding for Node: https://github.com/brianc/node-libpq
