A fairly large portion of our community is interested in build systems and scientific computing. A while ago the idea was proposed to migrate scipy (and after that also numpy) to meson. This effort is now underway.
As part of the effort Cython support was added to meson and will be released in 0.59.0.
An open question is still how to handle different blas/lapack providers, something we in Nixpkgs support. Given there are so many MKL users in our community you may be interested to have a look at that issue.
Finally, if you’d like to build the meson version of scipy with Nix, have a look at BLD: Scipy meson build with Nix by FRidh · Pull Request #41 · rgommers/scipy · GitHub.