Codex

We use Codex for code-level reasoning tasks that sit above autocomplete: reading an unfamiliar test suite and explaining what it actually covers, drafting a refactor across many similar files, and translating test logic between languages when a client is consolidating stacks. On inherited automation estates — where we often arrive with thousands of tests and no documentation — this is genuinely useful for building a map fast, though we verify the map by running the suite rather than trusting the summary. It is also effective at the mechanical part of migrations, such as converting a large body of tests from one assertion library to another, where the transformation is consistent and reviewable. As with all of these, output is treated as a draft: an engineer reviews before anything reaches a client repository, and we do not point it at production systems or client-confidential data.