Callosum develops system-level software that allows different AI chip architectures to interoperate, enabling flexible, sovereign AI infrastructure.
About Us The last era of AI scaled on a single bet: bigger models, more identical chips, more data. As problems grow more complex and the requirements of intelligence more diverse, that bet is breaking down. Real-world problems are heterogeneous: no single model or chip can solve them alone. The next era of AI requires heterogeneity at the infrastructure level - diverse models on diverse chips, each with distinct strengths, co-evolving into systems of capability that move the Pareto frontier of what is possible. That's what we are building. Callosum is the Intelligent Systems Company. We started from questioning what actually creates intelligence. We believe there is no single answer, but rather a system-level solution. We co-evolve models, workflows, and silicon together to show that intelligence does not come from a single component, but it emerges from the diversity of co-optimised mechanisms working together and aware of each other. Heterogeneity will define the next era of compute, and is a principle that holds in biological, neuronal, and economic systems alike. In early 2026 we launched with results showing orders of magnitude improvements in performance, and this is only the beginning. Agentic AI is the future of how intelligence is deployed: multi-step, long-horizon, and operating in changing environments. These systems are inherently heterogeneous, and can only be as powerful as the infrastructure that runs them. We are engineers and scientists based in London, working together 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.