Codex’s Comeback Up Close

Hello, and happy Sunday. This week, Dan Shipper told the story of how a small OpenAI team transformed Codex from a failed launch into the app that took over ChatGPT, remaking the entire company in the process. On Friday, Dan joined senior editor Jack Cheng and me for a behind-the-scenes discussion of the story, including how he used Codex to structure it while keeping his own voice. Also: Every subscribers can RSVP for free to the Thesis: 2027 after-party on November 5 at Pioneer Works in Red Hook, Brooklyn.—Kate Lee

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Knowledge base

“How Codex Happened” by Dan Shipper: A year ago, OpenAI’s coding effort looked lost: Codex Cloud had flopped, the Windsurf deal had fallen apart, and Claude Code was taking off. Then a tiny team in the “backwaters” of the company built an app that swallowed ChatGPT from the inside. Today, Codex and ChatGPT for Work together have 40 million weekly users. Dan Shipper spent months talking with the OpenAI team that made Codex happen, including Greg Brockman and Thibault Sottiaux, to learn what it takes to build when the frontier keeps moving. His story comes with prompts for applying the lessons to your own work, plus the full interview transcripts for paid subscribers.

Every software engineer Lee Knowlton turned Dan’s piece into an interactive visual novel. Watch a trailer for it, and play it here.

“Gemini 4 Argon Puts Google Back On the Frontier” by Katie Parrott/Vibe Check: Gemini 4 Argon brings Google back into the frontier pack, an impressive feat for a company that runs on Google Workspace. The model is strongest as a collaborator: Dan now switches to it to structure essays and sharpen metaphors, and Compound Engineering creator Kieran Klaassen found it a fast, capable prototyper even at its lowest effort setting. Left on its own, Argon overbuilds in prose and design, and its desktop app, Antigravity, feels six months to a year behind Claude Code and Codex.