London-based Callosum, whose software matches AI tasks with different models and chips, raised a $100M seed from Atomico, UK Sovereign AI Fund, and others (Bloomberg)

Callosum, a London-based platform that matches AI workloads to appropriate models and hardware, raised a $100 million seed round from Atomico, the UK Sovereign AI Fund and other investors. Stripe is acquiring New York-based OpenRouter for $7.5 billion, paying $1.5 billion to the startup’s founders and $6 billion to its investors, linking OpenRouter’s model-selection service with Stripe’s payments ecosystem.