How Codex is built - by Gergely Orosz
newsletter.pragmaticengineer.com/p/how-codex-is-built
What Jamie wrote
Pragmatic Engineer deep dive on OpenAI's Codex — 1M+ weekly users, Rust-based, writes 90%+ of its own code, changing engineering practices at OpenAI itself. Companion piece to the Claude Code deep dive. Highly relevant for CTOs thinking about AI-native dev workflows. Pull quote: "Codex itself writes more than 90% of the app's code, the team estimates."