Noam Shazeer, Gemini co-lead and transformer co-author, leaves Google for OpenAI

Noam Shazeer, co-author of the 2017 transformer paper that underpins modern large language models and co-lead of Google's Gemini models, announced on June 17, 2026 that he is leaving Google to join OpenAI. He made the announcement on X, stating he looks forward to working with the team at OpenAI.

Shazeer's departure comes less than two years after Google reportedly paid $2.7 billion to bring him back from Character.AI, the startup he co-founded after leaving Google the first time. That deal also brought a team of his researchers back to Google.

A Return That Didn't Stick

Shazeer is a vice president of engineering at Google and a co-leader of the Gemini effort. As one of the authors of "Attention Is All You Need", the paper that introduced the transformer architecture, he is among a small group of researchers whose work sits underneath ChatGPT, Claude, Gemini, and most of what the industry now calls AI. His decision to switch sides carries weight beyond a single hire.

OpenAI gains him at a particular moment. The company is widely reported to be heading towards an initial public offering, and adding a researcher of Shazeer's standing to work on new model architectures is both a research move and a signal to the market about who wants to be there.

• Shazeer co-authored the 2017 paper "Attention Is All You Need", which introduced the transformer architecture.
• He returned to Google in 2024 as part of a deal reportedly worth $2.7 billion that also brought back his Character.AI team.
• He served as vice president of engineering and co-lead of Google's Gemini models.
• He will join OpenAI to work on new model architectures, according to his announcement.
• His move is the second major AI hiring shake-up this year, following Andrej Karpathy's move to Anthropic.

Implications for the AI Talent War

For Google, the loss lands amid an intensifying contest with OpenAI and Anthropic across the enterprise AI stack. At Cloud Next this year the company rebuilt its AI platform around agents, consolidating products and lining up partners in an explicit bid to out-package its rivals. The Gemini models are central to that bet, which makes the exit of one of their co-leads more than a routine personnel matter.

The departure also reframes a debate inside the industry about whether enormous retention packages actually work. Google's reported $2.7 billion move to reacquire Shazeer and his Character.AI team was held up as evidence that the giants would pay almost anything to hold the people who build frontier models. His exit, so soon after, suggests money buys presence but not permanence, and that the pull of a company seen as the field's frontier can outweigh a nine-figure reason to stay.

Neither company has detailed the terms of Shazeer's move, his start date, or precisely what he will work on at OpenAI beyond new architectures. What is on the record is the announcement itself, made by Shazeer, and what it represents: less than two years after a multibillion-dollar effort to bring him home, Google's Gemini co-lead is walking across the street.