VWWHFSfQ, you may already know this, but: I recommend this talk by Armin Ronacher (Flask creator) on how Python's implementation internals contribute to the difficulties of making Python faster.

https://www.youtube.com/watchv=qCGofLIzX6g

One case study Ronacher gets into is the torturous path taken through the Python interpreter (runtime?) when you evaluate `__add__`. Fascinating stuff.