Google AI has experienced a rare personnel upheaval. Demis Hassabis, head of DeepMind, announced he would step down from daily management duties and take on the role of Chairman of DeepMind and Chief Scientist at Alphabet; almost simultaneously, Google's Chief Scientist Jeff Dean announced the end of his nearly 27-year career at Google, and he and three senior researchers co-founded a new company called Discovery Loop. After the announcement, Alphabet's stock price fell nearly 4% in one day.

Hassabis moves internally, Gemini 4 continues to progress

Hassabis has not left the company but transitioned from an organizational manager to a long-term strategist and chief science advisor. He said that his new position will allow him to focus more on AGI, breakthroughs in basic science, and global AI governance, while continuing to participate in AI drug development work at Isomorphic Labs. Daily management of DeepMind will be taken over by current CTO Koray Kavukcuoglu, who has worked with Hassabis for over 13 years and was involved in projects such as WaveNet and DQN. The development of the Gemini model, cutting-edge AI research, and related teams are now under his management. Hassabis revealed in a public letter that the next-generation model Gemini 4 is progressing well.

Jeff Dean brings half of AI history, Google invests in the new company

Compared to Hassabis's "internal transfer," Jeff Dean's departure caused greater shock. Dean joined Google in 1999, and over the past two decades, many key technologies at Google have been directly related to him, including early search infrastructure, MapReduce, BigTable, TensorFlow, and TPU. Along with him, three prominent figures also left: distributed systems expert Sanjay Ghemawat, technical lead of Gemini Oriol Vinyals, and early member of Google Brain Quoc Le—four of them have participated in projects including AlphaFold, AlphaStar, AlphaCode, and Gemini.

Discovery Loop's core focus is using AI to automate the scientific research cycle—generating experimental designs, executing analysis, and iterating research directions, allowing a large number of experiments to run in parallel. Dean revealed that he started seriously considering entrepreneurship about five weeks ago, and Pichai arranged multiple meetings to try to retain him. Despite the four leaving collectively, Google still invested in Discovery Loop and signed a cloud computing cooperation agreement. The seed round was led jointly by Khosla Ventures and Radical Ventures.

This personnel earthquake comes against the backdrop of Google AI facing multiple pressures. The flagship model Gemini 3.5 Pro was originally scheduled to be released in June, but it has been postponed multiple times and has not been launched yet; two weeks ago, Google announced an increase in AI capital expenditure without providing a new model release date, causing its stock price to drop about 7%. Previously, the author of the Transformer paper, Noam Shazeer, left Google to join OpenAI, and John Jumper, a core researcher of AlphaFold and Nobel Prize winner in Chemistry, moved to Anthropic. As the birthplace of the Transformer architecture, Google has nurtured some of the most important technological talents in the modern AI era—now some of them are beginning to leave, and Google needs to prove not only that it still has a world-class team, but also whether it can retain these people.