Callosum raises $100M in one of Europe's largest seed rounds
What's the deal? Callosum, a UK AI infrastructure startup building software that orchestrates workloads across different chips and models, has raised $100 million in a seed round led by Atomico. Plural, DCVC and UK Sovereign AIDealroom has a profile for this one. Try Dealroom → also participated, alongside angel investors.
Why now? The financing follows Callosum's $10.25 million seed round in February 2026, when the company emerged from stealth. Its software is designed to route each AI task to the model and hardware best suited to the job, rather than relying on a single model or chip architecture.
What it means: Callosum says this heterogeneous approach can make AI workloads faster and cheaper. The company has also announced a partnership with Cerebras Systems. Its work sits in a market shaped by the high compute costs associated with Nvidia, OpenAI and AnthropicDealroom has a profile for this one. Try Dealroom →.
The signal: A $100 million seed round is unusually large for European AI infrastructure, highlighting investor appetite for software that can reduce the cost and concentration of AI compute.
Read more: Tech.eu
Image credit: Callosum
