Thibault Sottiaux, professionally known as Tibo, is a Belgian software engineer and product leader recognized for his role as the engineering lead for Codex at OpenAI, as well as his subsequent responsibilities in overseeing OpenAI's core products, including ChatGPT and Codex. He holds a Bachelor of Applied Science and a Master of Science in Computational and Applied Mathematics from the Université catholique de Louvain (UCLouvain) in Belgium.

Education

Thibault Sottiaux earned his Bachelor of Applied Science and Master of Science degrees in Computational and Applied Mathematics from UCLouvain in Belgium. During his academic tenure, he contributed to computer science publications, notably on projects related to the Gemini family of multimodal models and Reverb, a system for experience replay in reinforcement learning. These contributions were made during his time working at Google. ^[1]

Early Career — Google

Thibault Sottiaux's early career was marked by his tenure at Google, where he held various software engineering and machine learning-focused roles, progressing from Software Engineer to Senior Software Engineer to Staff Software Engineer. Notably, Sottiaux served as the ML Workflow Lead, concentrating on enhancing machine learning infrastructure and tooling. In his role as the Gemini Human Data Lead, he led the development of data pipelines that support Google's Gemini multimodal model family. ^[1]

OpenAI — Codex Engineering Lead

In 2025, Thibault Sottiaux joined OpenAI, becoming the engineering lead for Codex, OpenAI's agentic coding system. Codex is designed to function within sandboxed environments and collaborate across various aspects of the software development stack. Sottiaux articulated the team’s "agent-first" approach, which emphasizes creating a general agent before determining specific product endpoints, as opposed to focusing initially on narrow use cases. ^[2]

Under Sottiaux's guidance, the concept of a "harness" was introduced — a lightweight software scaffolding that supports the agent but is meant to be phased out as model capabilities increase. ^[3] In March 2026, OpenAI acquired Astral, a Python developer tools startup, to support Codex's goal of improving developer efficiency; Sottiaux stated the acquisition would help accelerate that vision. ^[4]

Sottiaux discussed Codex's development publicly alongside OpenAI co-founder Greg Brockman on the OpenAI Podcast in September 2025. He appeared on Software Engineering Daily in January 2026 alongside Codex product designer Ed Bayes. He also initiated the "100 Days of Codex" program on social media platform X, spotlighting and rewarding individuals who leveraged Codex effectively. ^[5]

OpenAI — General Manager, ChatGPT and Codex

In 2026, OpenAI restructured its product teams into a unified organization, expanding Thibault Sottiaux's role from leading Codex to overseeing all of OpenAI's core products and platforms, including ChatGPT. With the title of General Manager, Sottiaux became a central figure in directing OpenAI's product strategy. During this period, he was featured in a Wired interview, discussing OpenAI's broader product direction. ^[6]

As the head of ChatGPT and Codex, Sottiaux appeared on the Silicon Valley Girl podcast in May 2026, where he elaborated on the trajectory of AI agents. Separately, Sottiaux outlined OpenAI's vision for a "personal agent" to the Financial Times, describing it as an assistant capable of helping users across all aspects of their professional and personal lives. ^[7]