Ineffable Intelligence hires six, including key fig…

Image: METAL AI

Summary

London AI startup Ineffable Intelligence has brought on six new co-founders: four from Google DeepMind, one from InstaDeep, and one from venture firm Flying Fish
The company raised a $1.1 billion seed round in April at a $5 billion valuation, the largest seed round in European history
George Rose, who actually incorporated the company, now serves only as an advisor, and David Silver has said he does not consider Rose a co-founder

AlphaStar veterans move from DeepMind to Ineffable

London-based AI startup Ineffable Intelligence has hired six new co-founders from Google DeepMind, InstaDeep, and venture capital firm Flying Fish, Fortune reported exclusively. Ineffable raised a $1.1 billion seed round in April at a $5 billion valuation — the largest seed round ever raised by a European startup.

George Rose actually founded Ineffable's corporate entity but now remains only an advisor, his connection to the company fading like a dotted line. Meanwhile, the six DeepMind veterans who joined later have secured the definitive title of co-founder, linked to Ineffable by a bold solid line. It shows that the company's legitimacy comes not from who incorporated it first, but from whose name and track record it brought in. — Image: Generated by METAL AI

What Ineffable Intelligence does

Ineffable is led by David Silver, who worked as a researcher at Google DeepMind before joining the company earlier this year. The company's stated goal is to build superintelligence that surpasses human capability, and it has chosen reinforcement learning as its path to get there. Reinforcement learning trains AI to discover through trial and error which actions maximize reward — a field Silver has long been known for researching.

What the six new hires bring to the table

Of the newly hired staff, four — Chris Apps, Wojciech Czarnecki, Lasse Espeholt, and Junhyuk Oh — all previously worked together at Google DeepMind.

Apps, Czarnecki, and Oh all worked on DeepMind's 2019 AlphaStar project, an AI system that beat world-class human players at the real-time strategy game StarCraft II.

To put it plainly: AlphaStar was the StarCraft II AI that Google DeepMind released in 2019, and it beat professional human players. Chris Apps, Wojciech Czarnecki, and Junhyuk Oh — now joining Ineffable — were the core people behind that AlphaStar development. In effect, the team behind one of DeepMind's signature achievements has moved to the new startup as a unit.

Oh led the reinforcement learning effort during AlphaStar's development and was, in 2025, among the early researchers using AI to discover new reinforcement learning algorithms. At Ineffable, he will head the company's reinforcement learning work.

Espeholt previously worked on Google's weather forecasting AI model MetNet, while Alexandre Laterre served as head of research at InstaDeep, the London AI firm acquired by BioNTech in 2023. Heather Goram was a partner at Flying Fish, the venture firm that was one of Ineffable's early investors.

Name	Previous affiliation	Role at Ineffable
Chris Apps	Google DeepMind	Head of Mission Acceleration
Wojciech Czarnecki	Google DeepMind	Head of Science
Lasse Espeholt	Google DeepMind	Compute, Infrastructure & Engineering Strategy
Junhyuk Oh	Google DeepMind	Head of Reinforcement Learning
Alexandre Laterre	InstaDeep	Head of Research Engineering
Heather Goram	Flying Fish	Head of Compute, Fundraising & Operations

Goram reportedly built her relationship with Silver by asking him about new reinforcement learning approaches starting in early 2024, while she was a partner at Flying Fish — a connection that made Flying Fish the first investor to put money into Ineffable. She was also involved in the large seed round led by Sequoia and Lightspeed Venture Partners, and reportedly played a role in securing the compute partnership with Google Cloud announced this past July.

The actual founder was someone else

According to records from the UK's Companies House, Ineffable's corporate entity was actually incorporated in November 2025 by George "Jody" Rose, a Canadian serial entrepreneur and investor. Silver did not appear on the company's board of directors until January 2026, after he had formally left DeepMind.

Records show that a month later, Rose was removed as a person with significant control over Ineffable's shares, and he stepped down as a director this past July. On his LinkedIn profile and personal website, Rose describes himself as a founding advisor. A company spokesperson said Rose, a friend of Silver's, helped get the company off the ground before transitioning into an advisory role, and that Silver does not consider him a co-founder.

The neolab wave and DeepMind's talent exodus

Ineffable belongs to a group of next-generation frontier AI companies often called "neolabs." Many of these companies, which have emerged over the past two years, were founded by people who left Google DeepMind, OpenAI, or Anthropic — among them Thinking Machines Lab, co-founded by former OpenAI CTO Mira Murati; Safe Superintelligence, founded by former OpenAI chief scientist Ilya Sutskever; and companies like Sakana AI, Reflection AI, Core Automation, and Adaption Labs.

According to Fortune, DeepMind has long been regarded as the first company to explicitly set human-level or superhuman AI as its core objective, but a growing perception has taken hold that the company is losing ground as a string of senior researchers depart for rival firms. Ineffable's simultaneous hiring of six people fits into that broader pattern.