Blomfield, 40, said he would take a leave of absence from his role as a partner at Y Combinator, the American start-up investor behind Airbnb, Stripe and Coinbase, to join Anthropic’s compute team. Compute is the industry term for the hardware, software and data centre infrastructure required to train and run AI models.
Writing on X, Blomfield said: “Powerful AI has the potential to improve the life of every human on Earth and, as we enter the early stages of recursive self-improvement, availability of compute becomes one of the most important issues to solve. I’m excited to get started.”
He will work alongside Tom Brown, Anthropic’s co-founder and chief compute officer. The hire is a coup for Anthropic, which this year overtook OpenAI to become the world’s most valuable private AI business.
For UK business owners the move carries a familiar sting. Blomfield is one of the country’s most influential angel investors in early-stage companies, and his energy is now heading into an American lab rather than the British start-up scene.
It also underlines quite how fierce the battle for elite AI talent has become. Technology groups including Meta and Alphabet, and dedicated AI firms such as Anthropic and OpenAI, are competing aggressively for researchers as they race to build next-generation systems.
Last month Andrej Karpathy, the AI researcher who co-founded OpenAI, joined Anthropic to work on the “pre-training” that underpins AI model development. He was joined by John Jumper, the Nobel prize-winning scientist who co-created AlphaFold at Google DeepMind, the breakthrough AI that has predicted over 200 million protein structures. Days earlier, Noam Shazeer, a vice-president of engineering at Google and co-lead of its Gemini models, said he would leave to join OpenAI. Rishi Sunak, the former prime minister, joined Anthropic as an adviser last year.
The stakes are rising because both Anthropic and OpenAI are preparing for blockbuster flotations, with OpenAI already lining up a confidential IPO filing, at a time when concerns are growing about a valuation bubble.
Blomfield launched Monzo, now widely expected to be a flotation candidate, in 2015, having earlier co-founded GoCardless, the payments company that recently agreed a sale worth nearly £1bn. He left Monzo in 2021 and has spoken openly about the toll that running the bank through the pandemic took on his mental health.
His departure for Anthropic will revive an uncomfortable debate he has led before. Writing in The Times in 2024, he said: “Our national psyche doesn’t allow for the celebration of entrepreneurs, we are extremely risk-averse, and the huge majority of smart, technologically adept young people in the UK aspire to be lawyers or consultants or work in finance.”
When he joined Y Combinator in 2023 he said there were more opportunities for entrepreneurs in the United States, and that problems with the attractiveness of London’s public markets to technology businesses were “very real”. That critique still lands: ministers are now making direct investments to keep high-growth AI firms listing in London.
Blomfield has previously written that “technological progress truly offers a path to a better world for all of humanity”, while warning that “technological progress is accelerating very rapidly and I don’t think most people are prepared for that future”.
For Britain’s SMEs, the message is double-edged. The AI boom is minting opportunity at extraordinary speed, but the people best placed to build it, including the founder of the UK’s flagship fintech, keep choosing to build it somewhere else.
Jamie Young
Jamie Young is Senior Reporter at Business Matters, covering SME finance, employment law and Westminster policy since 2016. He has reported on every Budget and Autumn Statement since 2018, helped make sense of the 'covid era' and the bounce-back loan scheme from launch through the fraud investigations, and broke the magazine's coverage of the 2024 late-payment reforms. He joined Business Matters straight from completing his BA in Administration from Exeter University and is NCTJ-qualified. Reach him at jyoung@cbmeg.co.uk
