Heads-up for anyone with Lambda functions still on python3.10. AWS deprecates the runtime on Oct 31, 2026. Functions keep running, but they stop getting patches, the console won't let you edit them, and in 2027 AWS blocks creating new ones (Jul 29) and then updating existing ones (Aug 31).

The Python side is the real work. A few things that bit people:

- distutils is gone in 3.12. Anything still importing it (old setup.py tooling, some older libraries) breaks. setuptools or packaging usually covers it.

- cgi, crypt and telnetlib are removed in 3.13 (PEP 594 "dead batteries").

- python3.12+ on Lambda runs on Amazon Linux 2023 instead of AL2, so compiled wheels and layers (numpy, psycopg2, cryptography and similar) need rebuilding.

- python3.11 is a short stop.…