Packaging tools for language/ecosystem X written in another language Y are always a red flag. They had to reinvent a bunch of wheels, such as parsing metadata, and they probably did it badly.

See also: uv.

Except uv is by far the best UX for Python package management out there. There's a reason they chose Rust to write this tool.

The same goes for typing.. mypy (written in Python, and contributed to by Guido himself) performed so poorly that they had to invent a bespoke compiler for it (mypyc). The other options written in Rust or node are much more performant.

Another example: the golang port of the Typescript compiler.

I agree with the take it's odd to write a nuget server in node, but the comparison to uv isn't fair. There's concrete reasons to choose a more performant language for the task.

FWIW, the NuGet package format and the v3 server protocol are fairly simple and well documented.

And so unnecessary. .NET is perfectly fine for that.

UV is different because python performance is dogshit when actual processing is involved. Most fast Python stuff is in C extensions so Rust is no surprise here.