The Compute 100: Jascha Achterberg, Co-Founder & CTO, Callosum

Today’s guest is Jascha Achterberg, co-founder and CTO of Callosum. Jascha started with his Cambridge PhD collaborator Danyal Akarca (CEO), London-based Callosum is building infrastructure that matches complex AI workloads to specialized models and chips. The company has raised a $100 million seed round led by Atomico, with significant participation from Plural, DCVC, and the UK Sovereign AI Fund. Jascha’s bet is that the future of compute is heterogeneous: different chips working together on different parts of a problem. We’ll dig into the commercialization opportunity: discover where each architecture excels, help chipmakers find production workloads, and let enterprises adopt new compute without replacing the stack they already trust. It is all in pursuit of faster, cheaper, and more capable computing systems, which is the biggest prize in infrastructure today. Beyond the multichip future, we discuss: What neuroscience taught Jascha about designing computing systemsHow chipmakers discover what their hardware is best atWhere thermodynamic, biological, and quantum computing could fitHiring people who welcome having their ideas challengedBuilding an AI infrastructure company in London Timestamps: 0:00 Introduction 2:55 What heterogeneous computing actually means 11:02 From PhD research to Callosum 18:36 Turning heterogeneous compute into a product 23:24 Sourcing compute and working with chipmakers 28:53 Matching workloads to the right hardware 34:24 What heterogeneous computing can do today 38:29 The next waves of chips 48:02 Building the team 51:33 Why build in London? 56:11 Helping enterprises upgrade their compute stacks 1:01:04 Fundraising and building momentum 1:03:40 Where specialization wins, and where it doesn’t And a few links mentioned in the show: Callosum’s recent results on heterogeneous inference deployments: https://www.callosum.com/blog/programmable-heterogeneity Blog post on Callosum’s theoretical research on heterogeneity across computing, economic, and biological systems: https://www.callosum.com/blog/the-principle-of-maximum-heterogeneity The Compute 100 is led by ⁠Brian Schechter⁠ and ⁠Gaby Lorenzi⁠, compute-focused investors at ⁠Primary⁠. Primary is a pre-seed and seed-stage venture firm that backs founders building across markets including compute, industrials, healthcare and vertical AI. With $1.6B AUM and a 60+ person operating team, Primary delivers unparalleled support to teams across recruiting, finance, GTM, and brand. Primary’s compute portfolio includes Etched, The Biological Computing Company, Haiqu, and Atero (acquired by Crusoe). The Compute 100 is led by ⁠Brian Schechter⁠ and ⁠Gaby Lorenzi⁠, compute-focused investors at ⁠Primary⁠. Primary is a pre-seed and seed-stage venture firm that backs founders building across markets including compute, industrials, healthcare and vertical AI. With $1.6B AUM and a 60+ person operating team, Primary delivers unparalleled support to teams across recruiting, finance, GTM, and brand. Primary’s compute portfolio includes Etched, The Biological Computing Company, Haiqu, and Atero (acquired by Crusoe). Follow us on ⁠X⁠ and check out our ⁠daily newsletter⁠. *This podcast is provided for informational purposes only and does not constitute an offer to sell or a solicitation of an offer to buy any security. Nothing discussed in this podcast constitutes investment, legal, tax, or accounting advice, or a recommendation to make any investment. Any views expressed are as of the date of recording, are subject to change, and may include forward-looking statements that involve risks and uncertainties.*