Do you have any code you can share showing this speed up? Because I have written a lot of Cython over past 5 years, and unless my python code is monumentally stupid (and in that case I can get an order of magnitude or two speedup by just writing sane python), I have never seen anything close to 100x speedup in real world code. Even getting a 5x speed up over a baseline python/numpy implementation requires a fair amount of refactoring to make the code more cython friendly.

Same with Numba, despite its promises, I've never seen anything close to 100x speedups in the real world, and I've even seen a fair few cases where numba resulted in slower code compared to 'pure' python/numpy (although admittedly that was 2-3 years ago)

Sure I could probably design some pathological code where you might see 100x speed up by just adding type annotations, but that would probably require starting with some really inefficient python code.