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.

About the Role

Callosum believes that orders of magnitude improvements in AI systems will come through application-aware orchestration across heterogeneous hardware. We are building that vision: infrastructure that treats the full landscape of compute as a unified, co-evolving system, evolved beyond GPUs. Current orchestration stacks were built for the homogeneous world - naive to the strengths of new chips and blind to the demands of modern multi-agent workflows.

This role defines how Callosum addresses this problem at the cloud and cluster level, transforming a fragmented compute ecosystem into a unified, exploitable resource pool. We are building the novel paradigm of orchestration that understands accelerator-specific constraints and capabilities. Your work is what makes heterogeneous compute intelligent at scale: every chip placed precisely and allocated efficiently in a stack that is resource-aware and diversity-native.

What You’ll Build

• Design and build multi-cloud orchestration systems that abstract provider-specific differences behind a unified deployment and scheduling layer

• Extend Kubernetes - particularly Dynamic Resource Allocation (DRA) — to be aware of heterogeneous accelerator topologies and capabilities, and multi-agent AI workflows

• Implement intelligent load balancing and placement strategies across cloud providers, regions, and hardware types

• Build control plane systems that enable efficient allocation and management of heterogeneous accelerator capacity while preserving the ability to exploit hardware-specific strengths

• Collaborate with an Accelerator Systems Software engineer to surface low-level scheduling primitives into the orchestration layer

What Sets You Apart

• Strong experience with Kubernetes internals - custom controllers, schedulers, device plugins, CRDs, and the DRA framework

• You've built or operated multi-cloud infrastructure and have a detailed understanding of the networking, storage, and compute differences between major providers

• Familiarity with GPU/accelerator resource management in cluster environments (e.g. MIG, time-slicing, device plugins, topology-aware scheduling)

• Experience with infrastructure-as-code, fleet management, and the reliability engineering required to keep large-scale heterogeneous systems running

What We Offer

• Competitive Salary, determined by skills and experience

• Equity & Ownership

• Private healthcare

• We offer Visa sponsorship and relocation benefits to hire the best in the world

• We work in person at our London office. You'll have the tools, space and setup to do your best work, and if you have specific needs, just tell us

We're committed to building an inclusive workplace where everyone feels welcome, and believe in equal opportunities for all.