I am the maintainer of rsyslog. This write-up is a field report from using AI coding tools in a mature C codebase of about 200k LOC.

The interesting part for us was not "can it generate code", but what had to change in the repo and workflow so the output became reliably useful: clearer contracts, better documentation near the code, stronger CI expectations, formatting consistency, and tighter task decomposition.

Happy to answer concrete questions, including where it worked, where it did not, and what still requires careful human review.