cinder: Instagram's performance oriented fork of CPython (via) Instagram forked CPython to add some performance-oriented features they wanted, including a method-at-a-time JIT compiler and a mechanism for eagerly evaluating coroutines (avoiding the overhead of creating a coroutine if an awaited function returns a value without itself needing to await). They’re open sourcing the code to help start conversations about implementing some of these features in CPython itself. I particularly enjoyed the warning that accompanies the repo: this is not intended to be a supported release, and if you decide to run it in production you are on your own!
Recent articles
- Wilson Lin on FastRender: a browser built by thousands of parallel agents - 23rd January 2026
- First impressions of Claude Cowork, Anthropic's general agent - 12th January 2026
- My answers to the questions I posed about porting open source code with LLMs - 11th January 2026