Tom Blomfield, a general partner at Y Combinator and cofounder of Monzo and GoCardless, announced this week he is taking a leave of absence from the accelerator to join Anthropic. Blomfield wrote on X that "availability of compute becomes one of the most important issues to solve" as AI enters "the early stages of recursive self-improvement." He will work on the compute team alongside Anthropic cofounder and chief compute officer Tom Brown. Blomfield was at YC as a partner after building two unicorns and was awarded an OBE in 2019 for his contribution to competition in banking. This move comes amid a hiring wave that has reshaped Anthropic's top deck in 2026, including Chemistry Nobel laureate John Jumper, OpenAI cofounder Andrej Karpathy, former Microsoft Azure AI president Eric Boyd, xAI cofounder Ross Nordeen, and UC Berkeley CS chair Jelani Nelson. Anthropic is scaling rapidly after closing a series G round earlier this year, valuing it at nearly $380 billion, with a subsequent raise pushing that figure towards $965 billion. Compute is the main bottleneck as Anthropic races to train and serve its next generation of Claude models.