My experience with Claude and Codex on a system architecture bug

Recently, I encountered a subtle bug in an event-driven system. Looking at the symptoms, the immediate defect looked clear to me but of late, for most bugs, I tend to rubber-duck it with an AI model before I make the fix. In the last few months, I have mostly used Claude but my employer recently rolled out initial support for Codex which also seems to be well regarded in the industry. I decided to do the back-and-forth with both models this time. I did not expect much difference in the results but I was a little curious how Codex would fare against Claude but also wanted to be exhaustive and make sure I don’t miss anything. ...

April 15, 2026 · 10 min