Callosum, a London-based startup, has raised €85.4 million ($100 million) in Seed funding. The company is building technology that helps businesses connect and manage different AI models and computer chips.
The company describes its approach as “heterogeneous intelligence,” which means making different AI systems and hardware work together more efficiently.
The funding round was led by Atomico, with strong support from Plural, DCVC and the UK Sovereign AI Fund. Other investors and angel investors also participated in the round.
The UK government launched its €573 million (£500 million) Sovereign AI initiative in April 2026. The programme is designed to support British AI startups developing technologies that are considered important for the country’s economic growth and national security.
“As AI moves from training to inference, the question is no longer just who builds the best models. It’s how we deliver intelligence efficiently, across an increasingly diverse landscape of models and chips,” said Niklas Zennström, CEO of Atomico.
Callosum was founded in 2025 by Jascha Achterberg and Danyal Akarca. The company believes the future of AI will not depend only on building the biggest AI model or owning the most powerful hardware. Instead, it sees an opportunity in making different AI models and types of computer chips work together efficiently.
Along with announcing the new funding, Callosum said it received the first investment from the UK Sovereign AI Fund. The company has also been selected as part of the UK government’s £1.1 billion AI hardware plan, which aims to strengthen the country’s AI computing capabilities.
“AI is nothing without the chips that underpin it – and the eye-watering demand for them is only going to grow. In the race to develop and use AI, success will depend not just on having access to those chips, but on using them as efficiently as possible,” said Kanishka Narayan, Minister for Artificial Intelligence, UK Government.
Callosum believes that new AI models and specialised AI chips are developing at the same time. The company says that making different models and chips work together could improve AI performance while also lowering costs.
As part of its Seed funding announcement, Callosum revealed three major developments to support this approach.
The first is a series of partnerships with computing and hardware companies around the world. This includes a major partnership with Cerebras Systems to provide faster, multi-agent AI services to customers at scale.
Callosum has also partnered with Rebellions, a chipmaker, along with other AI infrastructure providers and hardware companies.
