Exclusive: Ineffable Intelligence adds six "cofounders," hiring veterans from Google DeepMind, InstaDeep and venture firm Flying Fish

Ineffable Intelligence, the London AI startup launched this year by former Google DeepMind researcher David Silver, has added six high-profile “cofounders” to the team. That’s an unusual title for hires, and it signals how aggressively the company is trying to build around Silver’s reputation in reinforcement learning.

Four of the new arrivals are Silver’s former DeepMind colleagues: Chris Apps, Wojciech Czarnecki, Lasse Espeholt, and Junhyuk Oh. Apps, Czarnecki, and Oh all worked with Silver on AlphaStar in 2019, the DeepMind system that beat top human players at StarCraft II. Espeholt worked on Google’s MetNet weather prediction models. The fifth cofounder, Alexandre Laterre, led research at InstaDeep before that company was acquired by BioNTech in 2023.

The sixth is Heather Gorham, who had been a partner at Flying Fish, one of Ineffable’s earliest investors. She is now handling compute, fundraising, and operations, according to her LinkedIn profile. Ineffable confirmed the hires but declined to say more. All six recently updated their LinkedIn profiles to match the new roles.

The startup has already been moving fast. In April, it was valued at $5 billion after a $1.1 billion seed round, which Fortune described as the largest seed investment ever in Europe. Flying Fish wrote the first check, and later helped with the mega round led by Sequoia and Lightspeed Ventures. Gorham also helped secure Ineffable’s Google Cloud computing partnership, announced in July.

The hiring spree also fits a wider pattern. More DeepMind researchers are leaving for rival AI startups, feeding the idea that the lab that once made frontier AI its core mission is now under pressure. Ineffable is squarely in the “neolab” camp: a new frontier company aiming at superintelligence, but doing it through reinforcement learning, the area Silver is best known for. Oh will run that work, Czarnecki will oversee the science team, Apps will lead mission acceleration, Espeholt will handle compute and engineering strategy, and Laterre will oversee research engineering.