Callosum has raised $100m, six months after leaving stealth with a tenth of that, and the round includes money from the British state. Bloomberg reported the raise, describing the UK’s public AI fund as a backer.
The Cambridge company came out of stealth in February with $10.25m led by Plural, the fund founded by former Wise executive Taavet Hinrikus, alongside the government research agency ARIA and angels including Charlie Songhurst, Stan Boland, and John Lazar. Talks about a much larger round were reported in May, at up to $100m, or roughly £75m.
What Callosum sells is orchestration rather than silicon. Its software distributes an AI workload across mixed hardware, Nvidia, AMD, Google, and whatever else is in the rack, routing each part of a task to the chip and model that handle it best instead of assuming a homogeneous grid of GPUs.
The company claims that on complex agentic work, such as autonomous computer use, this delivers twice the accuracy, seven times the speed, and a quarter of the cost of a conventional GPU setup.
The founders are Danyal Akarca and Jascha Achterberg, who met while doing PhDs at Cambridge and have published in Nature journals, with stints at Intel and Google DeepMind between them. Their pitch is a direct bet against the prevailing architecture: “Big labs are currently betting that one model will rule them all,” one of them said at launch. “We think that’s wrong.”
