# Building Codex with Tibo Sottiaux

DevFeed: [Building Codex with Tibo Sottiaux](<https://devfeed.tech/articles/building-codex-with-tibo-sottiaux-18170.md>)

Original publisher: [Read original article](<https://newsletter.pragmaticengineer.com/p/building-codex-with-tibo-sottiaux>)

Author: Gergely Orosz

Published: 2026-09-09T15:57:24Z

Content type: article

Language: en

Sources: [The Pragmatic Engineer](<https://devfeed.tech/sources/the-pragmatic-engineer.md>)

Topics: [codex](<https://devfeed.tech/topics/codex.md>), [OpenAI](<https://devfeed.tech/topics/openai.md>), [Development](<https://devfeed.tech/topics/development.md>), [software-development](<https://devfeed.tech/topics/software-development.md>), [Command-line interface](<https://devfeed.tech/topics/cli.md>), [Git](<https://devfeed.tech/topics/git.md>)

Tags: [agentic](<https://devfeed.tech/tags/agentic.md>), [agents](<https://devfeed.tech/tags/agents.md>), [cli](<https://devfeed.tech/tags/cli.md>), [codex](<https://devfeed.tech/tags/codex.md>), [git](<https://devfeed.tech/tags/git.md>), [openai](<https://devfeed.tech/tags/openai.md>), [rust](<https://devfeed.tech/tags/rust.md>), [software-development](<https://devfeed.tech/tags/software-development.md>)

## AI overview

In a Pragmatic Engineer Podcast episode, OpenAI's Tibo Sottiaux discusses how Codex was built and iterated, including the Rust-based open-source CLI, evolving harness and models, support for multiple model providers, and use across software development tasks such as code reviews, maintenance, and system rearchitecture.

## Source excerpt

OpenAI's Tibo Sottiaux shares how Codex was built and how it's reshaping software development.