Breaking: Google's chief scientist has resigned, the CEO of DeepMind has stepped down, and the stock price has fallen by more than 5%.
Zhidx reported on August 6 that at 0:00 today, Google CEO Sundar Pichai released an open letter, announcing three major personnel changes at once:
(1) Former Google DeepMind CEO Demis Hassabis will step down from daily operational responsibilities, serve as Chairman of DeepMind and Chief Scientist of Alphabet. Going forward, his work will focus on the AGI strategic direction, global affairs, and Google's AI pharmaceutical company Isomorphic Labs;
(2) Former Google Chief Scientist Jeff Dean, who has worked at Google for more than 27 years, will leave to start his own business focused on automated AI, and Google will invest in Jeff Dean's startup;
(3) Google DeepMind CTO Koray Kavukcuoglu will take over the daily operations of Google DeepMind, be promoted to Senior Vice President of Google DeepMind, and continue to serve as Google's Chief AI Architect, undertaking the important responsibility of integrating Google's AI models and products. He will report directly to Pichai.
In the open letter, Pichai defined this change as the "next chapter" of Google's AI development. From the perspective of organizational structure, Google is transforming its AI research system that used to be dominated by top scientists into a management system that pays more attention to commercial implementation and daily operational efficiency, and spins off some cutting-edge explorations outside the core business.
Hassabis later posted on social media that he has devoted his whole life to the R&D of AGI, and this job adjustment will allow him to focus on long-term strategies, including accelerating scientific breakthroughs and using AI technology to cure diseases. Hassabis also mentioned in the open letter that Google's AI models (including the unreleased Gemini 4) have made "tremendous progress".
Jeff Dean posted on X that tomorrow will be his last day working at Google. Having witnessed Google grow from 25 people to more than 190,000 people today, Jeff Dean exclaimed that it has been an amazing journey.
Koray Kavukcuoglu, who took over the position, also posted on social media, saying that Google DeepMind will double down on the Gemini model, cutting-edge AI research, and products built for users and partners.
After the above news was announced, the share price of Google's parent company Alphabet fell by more than 5% at one point during intraday trading. As of 2:50 a.m. today, its share price fell by 4.17%.
This personnel change takes place at a critical node for Google DeepMind. On the one hand, Google's AI team is experiencing continuous brain drain: Noam Shazeer, one of the authors of the Transformer paper, left for OpenAI, and John Jumper, the Nobel Prize in Chemistry winner and core head of AlphaFold, joined Anthropic. The once prominent AlphaFold team has been completely disbanded.
On the other hand, Google's next-generation flagship model Gemini 3.5 Pro has failed to be released for a long time, and its release schedule has been repeatedly delayed. Google is pouring a large amount of resources into the AI programming direction promoted by co-founder Sergey Brin and others, but the lag in AI programming capabilities is also considered to be one of the main reasons for the delay of Gemini 3.5 Pro.
At present, Google still has the world's top AI talent team, computing power and scientific research accumulation. How to convert these advantages into leading models and products faster may be the main problem to be solved by this personnel adjustment.
01. Demis Hassabis: From a child prodigy in chess to a Nobel laureate, "stepping back from the front line" to bet on AI pharmaceuticals
For a long time in the past, Demis Hassabis could be regarded as the spokesperson of Google AI.
Hassabis was born in the UK and is of half-Chinese descent. He showed amazing intellectual talent in his youth, and reached the level of FIDE Master at the age of 13. At the age of 16, Hassabis entered the game industry, and later participated in the development of the classic simulation game Theme Park.
Demis Hassabis in his childhood
In 1997, Hassabis graduated from Cambridge with a Double First Class Honours degree in Computer Science, and then founded his own game company Elixir Studios in 1998. In 2005, driven by his interest in "intelligence" itself, he returned to academia and pursued a PhD in Cognitive Neuroscience at University College London (UCL), studying the brain mechanisms of memory and imagination.
In 2010, Hassabis co-founded DeepMind in London with Shane Legg and Mustafa Suleyman, with the goal of "solving intelligence first, and then using intelligence to solve all problems". In 2014, Google acquired DeepMind for about 500 million to 650 million US dollars, and Hassabis continued to lead DeepMind.
After that, DeepMind successively created a number of milestones in the history of AI: In 2016, AlphaGo defeated world Go champion Lee Sedol by 4:1; since 2018, the AlphaFold series of models have gradually conquered the protein structure prediction problem that has plagued the biology community for 50 years.
Demis Hassabis speaking at the AlphaGo vs Lee Sedol event
In April 2023, in response to the impact of ChatGPT, Google merged DeepMind and Google Brain into Google DeepMind, and Hassabis served as CEO to coordinate the development of the Gemini model. In 2024, Hassabis, John Jumper and David Baker jointly won the Nobel Prize in Chemistry.
After the latest transfer, Hassabis will serve as the newly created Chief Scientist of Alphabet and Chairman of DeepMind, while devoting more energy to Isomorphic Labs.
Isomorphic Labs is an AI pharmaceutical company spun off from DeepMind in 2021, with Hassabis himself as founder and CEO. Hassabis wrote in the letter: "I have always believed that the first major application of AI should be to improve human health. It is time for AI to prove its undoubted value to the world, and what better way to prove it than to help eventually cure diseases such as cancer?"
Core content of Demis Hassabis's open letter
02. Jeff Dean: The 27-year "Father of Infrastructure" at Google leaves to start a business, and the old employer turns into an investor
Jeff Dean's departure also attracted attention. The legendary engineer who joined Google in 1999 has served at Google for more than 27 years, witnessed Google grow from 25 people to a scale of more than 190,000 people today, and almost single-handedly laid the technical foundation of Google.
Jeff Dean announces that he is about to leave Google
In Silicon Valley's engineer culture, Jeff Dean has become a kind of "urban legend" exclusive to programmers: Google engineers once joked about his programming ability, making up the joke that "Jeff Dean can optimize the speed of light to go faster", and some people teased that the compiler will not report errors to Jeff Dean, because the compiler knows who to listen to.
The real Jeff Dean is indeed strong enough to support these legends. After joining Google, Jeff Dean and Sanjay Ghemawat, another founder of Google's infrastructure, worked together for a long time, leading the design of a series of infrastructures that supported Google's rise, including the distributed computing framework MapReduce, the distributed storage system BigTable, and the global distributed database Spanner, etc. These systems are still the foundation of Google and have become one of the technical models in the cloud computing era.
Jeff Dean programming
In 2011, Jeff Dean, Andrew Ng, a professor at Stanford University, and Google researcher Greg Corrado jointly founded Google Brain, opening up the industrialization path of deep learning at Google, with representative achievements including the deep learning framework TensorFlow and the machine learning platform AutoML.
After Google Brain merged with DeepMind in 2023, Jeff Dean transferred to the position of Google's Chief Scientist, reporting directly to Pichai. Until recently, he also co-led the development of the Gemini model with Oriol Vinyals and Noam Shazeer. The Gemini 3 released in November 2025 is widely recognized by the industry as narrowing the gap between Google's Gemini and the leading models of Anthropic and OpenAI.
After this departure, Jeff Dean announced that he will co-found a new company Discovery Loop with Sanjay Ghemawat, Oriol Vinyals (core researcher of AlphaGo and StarCraft AI AlphaStar), and Quoc Le (pioneer of seq2seq and AutoML), focusing on creating AI solutions that can automatically solve major problems in the fields of machine learning, science and engineering.
From left to right: Oriol Vinyals, Sanjay Ghemawat, Jeff Dean, Quoc Le
Discovery Loop will adopt the Public Benefit Corporation structure, which means that it may pay more attention to research missions than pure commercial returns. Google will continue to be tied to this group of veterans as an investor.
03. Koray Kavukcuoglu: Take full control of Google DeepMind and accelerate the integration of models and products
Koray Kavukcuoglu, who took over the daily operations of Google DeepMind, is a technical leader who grew up within the DeepMind system.
He was born in Turkey, studied aerospace engineering at Middle East Technical University for his bachelor's degree, then switched to computer science, and went to New York University to obtain his master's and doctorate degrees, under the tutelage of Yann LeCun, one of the three giants of deep learning.
Koray Kavukcuoglu
After graduating with a PhD, Kavukcuoglu worked briefly in the machine learning department of NEC Laboratories in the United States, and chose to join DeepMind, a little-known startup at the time, in 2012, becoming one of its early researchers.
After Google acquired DeepMind in 2014, Kavukcuoglu success