The OpenAI Engineer Behind ChatGPT’s Biggest Transformation

OpenAI is currently reshaping ChatGPT from the ground up. The company’s ambition is to evolve the chatbot’s basic interface into a personalized AI agent capable of managing everything in your personal and professional life. Internally and publicly, OpenAI has started calling this upcoming product a “super app.”

This all-in-one platform represents one of the most significant bets OpenAI has ever placed, and the responsibility for its success now rests heavily on one engineering leader: Thibault Sottiaux. Last month, Sottiaux was named OpenAI’s head of core products, putting him in charge of both ChatGPT and Codex, as well as the effort to merge them into the future super app.

To clear the path for this super app, OpenAI has already shut down several standalone products, including its video creation tool Sora and an AI platform designed for scientists. Many of the executives who led those teams have since departed, while Sottiaux’s influence within the company has only increased. He now reports directly to Greg Brockman, who oversees all of OpenAI’s product teams while Fidji Simo, the company’s CEO of AGI deployment, is on medical leave.

Sottiaux played a pivotal role in developing Codex, which has grown into one of OpenAI’s fastest-growing revenue streams. However, leading Codex meant catering to developers and collaborating with AI researchers. Now, he faces a new challenge: overhauling a consumer product with nearly a billion weekly active users.

“It’s incredibly exciting and mildly terrifying at the same time,” Sottiaux said in an interview earlier this week.

OpenAI has begun speaking publicly and frequently about its super app ambitions, but the exact functionality of the final product remains unclear. The term “super app” typically refers to platforms like WeChat in Asia, which combine messaging, payments, and shopping into a single interface. Yet OpenAI is planning something that appears far more ambitious.

Sottiaux explains that the goal is to create the “world’s best personal agent that deeply understands what humans care about.” Over the next year, he says ChatGPT will become “delightfully proactive,” delivering the right information at precisely the right moment.

By transforming ChatGPT into a super app, OpenAI hopes to reignite its growth as it races toward an IPO and fends off intense competition from Google and Anthropic. The company’s bet is that a single, personalized assistant for everything will reestablish OpenAI as the undisputed leader in consumer, enterprise, and the broader AI race.

Engineering Roots

Sottiaux grew up in Belgium and studied applied mathematics before joining Google’s London offices in 2015. There, he worked on Google Maps before moving to Google DeepMind, where he helped build the infrastructure and tools researchers used to create systems like AlphaGo. In 2016, AlphaGo made history by becoming the first AI to defeat a human Go champion.

When ChatGPT launched in 2022, Sottiaux felt inspired to move to San Francisco and find a way to work for OpenAI. “This is something that we had been sitting on at DeepMind for almost two years, and we were just not doing it,” he explains.

Sottiaux officially joined OpenAI in 2024, initially focusing on developing tools for the company’s own researchers, much like he had at DeepMind. Within a few months, however, he began building what would eventually become Codex. As the AI coding tool gained popularity, Sottiaux became a minor celebrity in the developer community, personally responding to bug reports on X and occasionally granting engineers’ requests to reset their weekly token limits.