For others curious, https://github.com/cockpit-project/cockpit shows that it's written in several languages, with C at the #1 place, with JS and Python following. "src/cockpit" (main backend logic?) is Python.
The new bridge is written in Python and when time comes we want to rewrite our webserver into some modern.
And I also find it really interesting to see whether a product is programmed using one clear stack or a mixture.
I know some languages and ecosystems much better than others, so I have an idea how well I could support it up-front if needed. Others have different deployment styles, ranging all the way from "just copy this one binary somewhere" to "first install this language interpreter with a fricken curlpipe, then this language-specific package manager, then these hundreds of dependencies, then our app if you're still awake. But don't forget you'll still need an application server..."
The widespread use of Docker has made the last even less common, but I still run into docker containers just don't work, and I don't know the tech stack, and learning a whole tech stack just to troubleshoot someone else's broken code in order to try it out is not my most favoritest use of time.