Noam Shazeer, transformer co-inventor and Google Gemini co-lead, leaves to join OpenAI

Noam Shazeer, vice president of engineering at Google and co-lead of the company's Gemini AI models, announced on June 17, 2026 that he is leaving to join OpenAI. The move represents one of the most significant AI talent shifts in the industry since Shazeer's original return to Google in 2024, when the company acquired his startup Character.AI in a $2.7 billion deal. He is also one of the co-authors of the landmark 2017 paper "Attention Is All You Need," which introduced the transformer architecture that underlies virtually every major AI model in existence today.

What's new

Shazeer confirmed the move on social media, writing that he was "incredibly proud of the amazing team at Google and everything we've built together" and expressing that it was "a difficult decision to move on." He said he looks forward to working with the "exceptional team" at OpenAI.

Google acknowledged the departure: "We are grateful for Noam's meaningful contributions to Google over the years."

Shazeer had been at the center of Google's Gemini development since returning to the company in 2024. Before founding Character.AI in 2021, he had been a senior researcher at Google Brain, where he was instrumental in large-scale language model development. His original departure from Google came after the company declined to release his LaMDA conversational model publicly.

Context

The move comes as OpenAI prepares for an IPO, having filed confidentially with the SEC in early June 2026. It also comes alongside leaked financial documents showing OpenAI generated $13.07 billion in revenue in 2025, and as the frontier AI talent market remains intensely competitive.

Shazeer's transformer paper co-authored with Illia Polosukhin, Ashish Vaswani, and Jakob Uszkoreit among others described the self-attention mechanism that made large-scale language modeling tractable and efficient. Without the transformer, neither GPT-4, Gemini, nor Claude would exist in their current forms.

Google had invested heavily to keep Shazeer in-house: the $2.7 billion deal for Character.AI in 2024 was in part a bet on retaining him as a Gemini architecture lead. His departure to a direct competitor is a significant talent loss at a critical moment for Google's AI efforts.

Why it matters

The departure of the transformer co-inventor from Google to OpenAI is more than a headline. Shazeer carries deep architectural intuition about the technical foundations that power current-generation models, and his presence at OpenAI signals potential architectural work on whatever comes after the current transformer paradigm.

For Google, the loss comes as Gemini faces increasing competitive pressure from Claude Fable 5 and the GPT-5 series. Retaining key researchers has been a persistent challenge for Google DeepMind, which has seen several departures to startups and competitors over the past two years. For OpenAI, the hire further bolsters a technical team that is already leading on frontier model capability benchmarks.