Callosum and Starcloud secure major funding for AI infrastructure

London-based AI infrastructure startup Callosum has raised $100 million in a seed funding round, one of the largest in Europe. Led by Atomico with participation from Plural, DCVC, and the UK Sovereign AI fund, the company develops software that optimizes AI workloads by routing tasks to the most efficient models and hardware. This approach, inspired by the specialized circuits of the human brain, aims to reduce costs and increase speed. Callosum has partnered with Cerebras Systems to integrate specialized inference accelerators into its platform.

Separately, Redmond-based Starcloud has secured a $250 million Series A extension, bringing its valuation to $2.3 billion. The company is building orbital data centers designed to perform AI inference and training in low Earth orbit. Starcloud aims to leverage the advantages of space, such as continuous solar power and easier cooling, to run advanced GPUs like the Nvidia H100. The capital will be used to expand manufacturing and secure launch capacity for upcoming satellite generations, including the Starcloud-3, which is intended for use with SpaceX’s Starship.