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.

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Timestamps:

00:00:00 - Start

00:01:27 - 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