I burned about $500 for this fun project: Small Python. Initial PoC used 3 resets of Codex in one session but all later development happens in Claude Code, also in one Opus 5.5 session over three days.

The outcome is a quickjs-like implementation for Python. Almost full Python 3.15 language features plus builtins are covered. No Lib/ support. Great for embedding scenarios.

No rust. Just plain C11 code.

Repo is here: https://github.com/soasme/small-python/

Ask me anything.