Callosum, a UK-based startup, has raised a $100 million seed round to build an integration platform aimed at making AI and other compute-heavy workloads faster, cheaper, and more energy-efficient by allowing multiple hardware and infrastructure vendors to work together. The round, one of the largest seed raises in European history, was led by Atomico, with significant participation from Plural, DCVC, and the UK Sovereign AI Fund, marking the government fund’s first named investment since its £500 million commitment to sovereign AI computing.
Founded by CEO Danyal Akarca and CTO Jascha Achterberg, former neuroscience researchers at Cambridge University, Callosum applies neural network principles to computing infrastructure, arguing that AI runs most efficiently when multiple vendors operate in concert rather than competing in isolation. Achterberg described the industry as reaching an inflection point requiring greater interoperability among complementary providers.
The company has secured partnerships with chipmakers including Cerebras, Rebellions, Axelera AI, NVIDIA, AMD, and Intel, alongside Supermicro, Normal Computing, AWS, and Furiosa. Notably absent are AI model companies, which Achterberg said would be added later, likely beginning with open-source developers.
Atomico framed the investment around resilience and sovereignty, noting that distributing workloads across multiple vendors prevents any single company from controlling access to intelligence, a concern increasingly tied to national security.
