OpenAI's Codex: This Model Is So Fast It Changes How You Code

OpenAI’s hottest app isn’t ChatGPT—it’s Codex.In the last few weeks alone, the Codex team shipped a desktop app, GPT-5.3 Codex (a new flagship model), and Spark, the fastest coding model I’ve ever used. Usage has grown fivefold since January, and over a million people now use Codex weekly. Codex was also the app that OpenAI chose to run an ad for in the Super Bowl.Dan Shipper talked to Thibault Sottiaux, head of Codex, and Andrew Ambrosino, a member of technical staff who built the Codex app, for Every’s AI & I about what OpenAI is building and how they’re using it internally.If you found this episode interesting, please like, subscribe, comment, and share! Want even more?Sign up for Every to unlock our ultimate guide to prompting ChatGPT here: https://every.ck.page/ultimate-guide-to-prompting-chatgpt. It’s usually only for paying subscribers, but you can get it here for free.To hear more from Dan Shipper:Subscribe to Every: https://every.to/subscribe Follow him on X: https://twitter.com/danshipper Head to granola.ai/every and get 3 months free with the code EVERY.Timestamps:  00:00:00 - Start00:01:27 - Introduction 00:05:27 - OpenAI's evolving bet on its coding agent 00:09:42 - The choice to invest in a GUI (over a terminal) 00:20:38 - The AI workflows that the Codex team relies on to ship 00:26:45 - Teaching Codex how to read between the lines 00:28:45 - Building affordances for a lightening fast model 00:33:15 - Why speed is a dimension of intelligence 00:36:30 - Code review is the next bottleneck for coding agents 00:41:24 - How the Codex team positions against the competition Links to resources mentioned in the episode:Thibault Sottiaux: Tibo (@thsottiaux)Andrew Ambrosino: Andrew Ambrosino (@ajambrosino)Every’s vibe check on everything the Codex team launched: OpenAI's Codex App Gains Ground on Claude Code, GPT-5.3 Codex—The 10x Engineer, Now More Fun at Parties, AI as Fast as Your Train of Thought