Hey! I work for a company where we actually have to code this sort of stuff, so I was making up some problems to give to people applying for jobs :)
I tend to use numpy because I think providing the numpy library is a good hint and its documentation is a nice list of things you could do (plus my machine learning + Matlab background), but I totally agree that it can be done other ways.
Here, check out some music that we make
https://www.youtube.com/watch?v=vHxSMp3jQIw