Callosum raises $100m to make AI workloads cheaper, with the British state on the cap table

Callosum secured $100 million to scale its AI-workload orchestration platform, which dynamically routes tasks across heterogeneous hardware—Nvidia, AMD, Google, and others—to achieve up to twice the accuracy, seven-fold speed gains and 75% lower cost versus conventional GPU clusters. The round includes an undisclosed investment from the UK’s £500 million Sovereign AI Unit, making it the first equity stake by the public AI fund, alongside private investors such as Plural, ARIA and several angels.