Ken Jin 5 July 2025 This blog post includes my honest opinions on the CPython JIT. What I think we did well, what I think we could have done better. I’ll also do some brief qualititative analysis. I’ve been working on CPython’s JIT compiler since before the very start. I don’t know how long that is at this point … 2.5, maybe almost 3 years? Anyways, I’m primarily responsible for Python’s JIT compiler’s optimizer. Note that at this point of time, the JIT is still experimental. This means it’s not...