Why Codex works better than Claude Code for my production monolith

Description

Over the last year I mostly used Codex, but during the last month I tried Claude Code with Opus 4.6 and 4.7. These are my notes. This is not a benchmark. It is just my experience from daily use on one production codebase. For some medium-complexity tasks, I also ran both tools with the same prompts, but I did not try to make this a controlled evaluation. TL;DR: for my production Python monolith, I still prefer Codex. The codebase is a many-years-old Python backend. It has several architect