Seed · AI & Machine Learning · London, United Kingdom · Founded 2025 · 16–16 employees
Callosum is a London-based AI infrastructure company founded in 2025 by Cambridge neuroscientists Danyal Akarca (CEO) and Jascha Achterberg (CTO), who built software that orchestrates AI workloads across heterogeneous chip architectures — including Nvidia, AMD, Cerebras, and custom silicon — without requiring code changes. The company's core insight, inspired by how the brain uses specialised circuits, is that chip diversity is an advantage to be exploited rather than a liability to be managed. In February 2026, Callosum raised a $10.25M pre-seed led by Plural with ARIA and notable angels; just six months later in August 2026, it raised a $100M seed round — one of Europe's largest ever — led by Atomico, with participation from Plural, DCVC, and the UK Sovereign AI Fund. With partnerships with Cerebras, Rebellions, and Axelera AI, Callosum is positioning itself as the essential routing layer between AI applications and the compute that runs them, delivering claimed 4x cost reductions and significant speed improvements over single-hardware approaches.