Google DeepMind is shedding its two most prominent leaders in a single, seismic day. Demis Hassabis is stepping away from day-to-day operations to become Alphabet’s Chief Scientist, while Jeff Dean, an engineer whose work underpins the modern AI era, is leaving the company entirely after 27 years to start a new venture.

Hassabis framed the move in almost messianic terms in a note to staff, calling this “a pivotal moment in human history” and asserting that AGI is now “close at hand.” He’ll keep a hand in “strategic and global AGI matters” with Sundar Pichai but is clearly pulling back to focus on what he calls “the big picture.” That picture includes more time at Isomorphic Labs, Alphabet’s AI drug discovery unit, where Hassabis has long argued AI’s top application should be improving human health. The day-to-day reins now go to Koray Kavukcuoglu, a 13-year DeepMind veteran who previously served as CTO and Google’s chief AI architect. He’ll report directly to Pichai and own everything from Gemini model development to the Gemini app.

Dean’s departure is the more jarring of the two. He’s teaming up with fellow Google legend Sanjay Ghemawat to launch Discovery Loop, a public benefit corporation with the sprawling ambition of automating machine learning, science, and engineering to accelerate discovery. The initial focus is automating large-scale ML experiments, but the roadmap stretches across scientific fields. That’s a direct shot at the future of research itself, and it puts Dean in loose competition with Anthropic and OpenAI, both of which have flagged faster, automated science as part of their own long games. Discovery Loop’s other co-founders are heavy hitters too: Oriol Vinyals, who co-led Gemini and helped build AlphaStar, and Quoc Le, a Google Brain co-founder whose sequence-to-sequence work laid the tracks for modern translation models.

What’s unspoken is as telling as what’s announced. Dean’s farewell post on X thanked colleagues but didn’t mention Google or his nearly three decades there — an omission that’s practically unheard of for a departing executive of his stature. It lands at a moment when Google is visibly scrambling to close the gap in coding AI, where its best models have slipped behind those from OpenAI and Anthropic. The company is betting on Gemini 4, a “much larger” model now in training, to claw back ground. No release date has been set. Radical Ventures and Khosla Ventures are leading Discovery Loop’s seed round, with Alphabet signing on as a cloud partner and backer — a tidy arrangement that keeps the mothership tethered to Dean’s next act even as he walks out the door.