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 As a Product Manager - Applied AI, you'll the bridge between Callosum's customers and the researchers building our intelligent systems. You translate what a customer's systems and stakeholders need into work researchers can build against, and translate what they build back into something a customer's engineering and leadership trust. This is not a backlog-and-roadmap role. You go deep enough into a customer's stack to understand how their workflows are structured and how a deployment behaves in their environment, then carry that understanding into how researchers prioritise, build, and benchmark, and how our engineering team can ultimately deliver a solution. You understand code and follow architecture discussions, but you do not write production code. You will work closely with the researchers designing new agentic workflows, with our Applied AI engineers and benchmarking engineers who validate them in production, and directly with senior technical stakeholders on the customer side. Responsibility and scope grow with what you demonstrate. WHAT YOU'LL BUILD - Scoping customer workflows, constraints, and requirements into work researchers can build against - Acting as the technical point of contact for senior stakeholders inside customer accounts, end to end - Carrying customer context to researchers, to applied AI engineers, and to benchmarking - Defining what the product needs to look like for a given deployment, from the customer's actual use case - Building the methodology and standards for how the function engages with enterprise customers - there's currently none WHAT YOU BRING - Technical foundations strong enough to read code, follow architecture discussions, and reason about how agentic systems get deployed - a CS or related STEM degree, or equivalent depth - 5+ years, most likely spent in consulting (strategy or technology, enterprise clients) or venture/operating roles with comparable enterprise exposure, having chosen a customer-facing path over software engineering - A track record operating in front of senior stakeholders at large organisations - Comfort with ambiguity - there's no playbook for this function yet WHAT SETS YOU APART - Technical project work from consulting that put you inside a customer's codebase or alongside their engineering team, not just stakeholder management - Experience at an AI-native or agentic product company in a customer-facing PM role - Experience deploying or operationalising LLM-based systems inside an enterprise environment - Strong academic record from a leading technical programme 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.