Expression of Interest - Internships in London

About Us

We’re living through a Cambrian explosion of intelligence: new models and new chips, each specialised for different tasks, are arriving all at once. The result is a new era for AI, one of radical heterogeneity. Callosum is the Intelligent Systems Company. We believe the next generation of AI won't be defined by any single model or chip, but by intelligent systems in which hardware and intelligence co-evolve. We are building the infrastructure that unifies heterogeneous compute across the full stack. This opens a new axis of scaling intelligence: a dynamic system that tailors itself to what each workload actually needs, whether that's speed, cost, precision, or whatever unit comes next.

The last era scaled on a different bet: one bigger model, more of the same chip, more data. That bet is running into structural limits. Frontier models offer extraordinary capability at unsustainable cost, one that today's monolithic infrastructure was never designed to serve.

Our founding principle is that intelligence comes from many specialised systems working together, not from any single component. We build the software orchestration layer that co-evolves models, workflows and silicon into one system, delivering inference tailored to every workload, and demonstrating orders-of-magnitude leaps in capability and cost.

Because our software spans the full stack, our engineering team works directly with heterogeneous accelerators and frontier silicon, including Cerebras, d-Matrix, Intel, NVIDIA, AMD, Normal Computing, Tenstorrent, GreatSky, and Mixx. We are not stopping at today's chips: each new generation of silicon unlocks algorithms that couldn't run before, and we intend to be first to them, every time. If we get it right, it will belong to everyone building on it - not to any single vendor.

In our latest funding round, we raised $100M, led by Atomico with participation from Plural, DCVC and the UK Sovereign AI Fund’s first investment. With this, we are building the infrastructure for the next era of intelligence.

We are engineers and scientists based in London, working across the full depth of the stack. We are curious, intellectually honest, and building what doesn't exist yet. If you thrive on uncharted territory and are energised by the scale of the challenge, we'd love to hear from you.

Internship - Expression of Interest

We're always interested in hearing from exceptional students who want to work on the hardest problems in AI infrastructure - bringing novel accelerators to life, building the systems that orchestrate them, and charting the new territories of what heterogeneous compute can do.

There's no formal internship programme or fixed cycle here - internships happen when the need and the right person come together. This form is how we keep track of who to reach out to when that happens. If you think you have unique skills to contribute, or are studying or have experience in any of the following, we'd love to hear from you:

• High-performance systems and low-level performance engineering
• Inference infrastructure, orchestration, or distributed systems
• Hardware bring-up, kernel development, or accelerator programming
• Simulation, modelling, or workload design

This is a general interest form rather than an application for a specific internship. We review all submissions on an ongoing basis and will reach out when we see a strong match and the right opportunity comes up.