Noam Shazeer cost Google $2.7 billion to bring back. He lasted less than two years. The vice president of engineering and Gemini co-lead announced on Wednesday that he is leaving to join OpenAI, and with him goes one of the people most responsible for Google clawing its way back into the AI race.

He called it a "difficult decision to move on" in a post on X. The man helping the ChatGPT maker now is the same one who helped Gemini catch ChatGPT in the first place.Shazeer doesn't undersell what he brings. His LinkedIn bio names him the "Inventor of the LLM revolution including Transformer and Mixture of Experts," a reference to "Attention Is All You Need," the 2017 paper he co-authored that the industry treats as the moment modern AI began.

Noam Shazeer's $2.7 billion return to Google ends in under two years

Shazeer goes back to the start at Google. He joined in 2000, stayed two decades, and built things that ranged from the company's early ad system to its deep learning work. Then in 2021 he left to co-found Character. AI with Daniel De Freitas, walking out after Google passed on a chatbot the two had pushed for internally. The irony wrote itself when Google came calling again in August 2024. The Wall Street Journal pegged the deal at $2.7 billion for non-exclusive rights to Character.

AI's technology, bundled with terms that put Shazeer back on Google's payroll. The startup stayed a separate legal entity.For a while it looked like money well spent. Google handed him a Gemini co-lead role, and he became one of the names credited with closing the gap on ChatGPT. Which is exactly why this hurts. The exit comes weeks after Google showed off Gemini 3.5 Flash and its Spark agent at I/O, and now the architect behind that comeback is walking to the other side.

Sam Altman wanted Noam Shazeer at OpenAI since day one, it took 10 years

Sam Altman wasn't subtle about how badly he wanted him. The OpenAI CEO posted that Shazeer "is one of the people I have most wanted to work with since the very beginning of openai," noting it "only took 10 years" and predicting it would be "worth the wait." Shazeer kept his own goodbye warm, thanking the team and saying he was proud of "everything we've built together.""It has been an honor and a pleasure to work with all of you," he wrote.

Noam Shazeer's OpenAI jump keeps the AI talent war red-hot

A single hire making headlines tells you how tight the market for AI talent has become. OpenAI, Google, Meta, and Anthropic are all writing enormous checks and engineering elaborate acqui-hire deals to move researchers across the lines, and Shazeer is among the biggest names to switch jerseys.He doesn't arrive without friction. Last November, the Information reported that Google moderators cracked down on his internal posts after he made controversial comments about transgender people and accused some colleagues of antisemitism.

He was reportedly pulled from an internal channel over it, though no disciplinary action followed.His landing spot is a company on the verge of going public. OpenAI confidentially filed for an IPO earlier this month, lining up one of the most watched tech listings in years. Altman finally gets the engineer he chased for a decade. Google gets a lesson it already knew: in this market, nobody stays bought.