UK AI infrastructure company Callosum has raised $100 million in seed funding, led by Atomico with participation from Plural, DCVC, and the UK's sovereign AI fund. The company builds an AI scheduling layer that automatically picks the right model and chip for each task, aiming to cut costs and latency without sacrificing quality.
It goes a layer deeper than typical model routing. A complex task can be broken into smaller subtasks, each assigned to a different "model + chip" combination. Simple steps can run on cheap, small models; speed-sensitive jobs get handed to Cerebras; other tasks can be spread across GPUs or dedicated AI accelerators.
In benchmarks Callosum has published, some combos delivered the same accuracy at up to one-twelfth the cost of GPT-5, and up to 5.5x faster.
The investment also marks the first equity stake from the UK's £500 million sovereign AI fund. Callosum also announced a partnership with Cerebras, after already integrating chipmakers like Rebellions and Axelera AI.