There’s native modules to speed up hot paths, and there’s writing 29% [0] of your framework in Rust, entirely sidestepping interoperability standards, like ASGI.

[0] https://github.com/sparckles/Robyn says 50% Python, 25.3% JS, 20.7% Rust — but all the JS code seems to be for their docs site, so it is reasonable to say 20.7 / 70.7 = 29.2% is in Rust.