Callosum

Callosum builds infrastructure that combines heterogeneous chips and AI models. Its product, Tailored Inference, is offered through APIs and matches a customer's workload to models, algorithms and hardware, with the stated aim of improving speed and cost efficiency.

Customers are described as companies running AI inference at scale and silicon or systems companies that want their architecture reachable through a standard endpoint. The company offers access to accelerators through partnerships with silicon companies; the website does not describe pricing or revenue details.

The company is based in London, where all 12 listed open roles are located, and was founded by Jascha Achterberg and Danyal Akarca. It states that it is backed by Atomico, Plural, DCVC and the UK Sovereign AI fund, alongside 30+ investors, and is supported by ARIA. Open roles cover research engineering, inference engine development, accelerator systems software, networking, security and internships.

Product: Tailored Inference: an API layer that routes and tunes AI workloads across models and hardware accelerators from partner silicon companies.