YC partner Tom Blomfield announced that he is leaving Y Combinator and joining Anthropic’s compute team

Y Combinator partner Tom Blomfield announced that he is taking a leave to join Anthropic and throw himself into the AI compute resource war.
(Background: Anthropic’s valuation has skyrocketed to $1.2 trillion, surpassing OpenAI! Even in the secondary market, people are going berserk—house sales are being fought over like crazy.)
(Additional context: Anthropic will pay SpaceX $1.25 billion per month in exchange for xAI excess compute.)

Table of contents

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• Why a YC partner chose to switch jobs now
• Anthropic’s compute arms race: from renting GPUs to recruiting talent
• Who Tom Brown is

Y Combinator (YC) partner and former Monzo bank co-founder Tom Blomfield announced on X on July 13 that he will temporarily take a leave from YC to join the compute team at AI foundation model company Anthropic, working alongside Tom Brown, the inventor of DALL-E 2.

In his post, he said that AI is entering an early stage of “recursive self-improvement,” and that compute supply has become one of the core problems determining how fast AI develops.

Why a YC partner chose to switch jobs now

During his time at YC, Blomfield helped startups screen and incubate. YC is the world’s most well-known Silicon Valley accelerator, and it has incubated more than 400 unicorns, including well-known startups such as Stripe, Vercel, and Airbnb. Blomfield himself is also the co-founder of Monzo, the first digital bank in Silicon Valley, with extensive experience in both fintech and AI.

This time, when joining Anthropic, Blomfield clearly stated the mission objective: to solve the problem of obtaining AI compute resources. As the Claude series of models continues to expand the scale of its parameters, Anthropic’s compute needs are also rising in tandem—requiring more dedicated specialists to manage the supply chain, infrastructure planning, and compute strategy.

Anthropic’s compute arms race: from renting GPUs to recruiting talent

Anthropic’s level of investment in compute is second to none among technology giants:

• In May this year, it signed a $45 billion long-term compute contract with SpaceX, paying $1.25 billion per month in exchange for xAI’s Colossus supercomputer’s remaining compute capacity
• It also simultaneously signed a long-term HBM memory supply agreement with Micron to ensure AI chip memory won’t run short
• Recently, it was further reported that it is working with Samsung to develop customized AI chips, preparing to challenge Nvidia’s GPU dominance

This recruitment of Blomfield can be seen as an extension of Anthropic’s strategy of making bets on both the “software layer” and the “supply chain layer.” Blomfield brings experience in startup equity selection and business strategy, while Tom Brown brings expertise in model training. Together, the two will focus on the core challenge of making AI compute “cheaper and more accessible.”

Who Tom Brown is

Tom Brown is an early core figure at Anthropic. His best-known achievement is that in 2021, at OpenAI, he helped develop DALL-E 2—the breakthrough model that brought “AI image generation” into the mainstream. After joining Anthropic, he continued to lead model training and compute allocation strategy.

Now, with Blomfield’s business background added, Anthropic’s plans for its compute supply chain will become even more diversified, and it also signals that the core battleground of AI competition is shifting from “model capability” to “compute scale.”