Develops software to distribute AI computing across different processor types.
Visit callosum.com ↗Callosum is looking for engineers to build AI infrastructure that orchestrates heterogeneous accelerators in London. Responsibilities may cover high-performance systems, inference, distributed systems, kernel development or accelerator programming.
Callosum is looking for a systems software engineer to develop kernels, drivers, firmware and runtime tools for heterogeneous accelerators. The role is based in London and involves optimising performance and integrating new hardware platforms.
Callosum is hiring a Member of Technical Staff to develop inference engines suited to heterogeneous hardware architectures. The role, based on site in London, focuses on SGLang, vLLM, and optimising scheduling, memory and execution.
Callosum is looking for a Member of Technical Staff specialising in inference performance and deployment in London. The role involves deploying and benchmarking models, optimising orchestration and analysing performance across heterogeneous hardware infrastructure. Experience deploying models in production, working with multi-node GPU environments and using frameworks such as Triton Inference Server is expected.
Callosum is hiring a Member of Technical Staff specialising in networking systems and interconnects for heterogeneous accelerators. The role involves developing high-performance data transfer mechanisms, particularly using RDMA, programmable NICs, DPUs and accelerator interconnects. The team works on site from the London offices, with competitive compensation, equity, private healthcare and mobility support.
Callosum is hiring a Research Engineer to design a reproducible benchmarking system that evaluates agentic and algorithmic solutions for LLMs. The role involves building sandboxed execution systems, analysing real traces and commits, and publishing external benchmarks. The offer mentions a competitive salary, equity, private healthcare and visa and relocation support.
Callosum is hiring a Member of Technical Staff in London specialising in evolutionary optimisation and AI systems. The successful candidate will develop an LLM-guided search loop to generate, evaluate and improve programmes across complex optimisation spaces. The role involves designing search strategies, continuous benchmarks and reusable software infrastructure.
Callosum is hiring an ML Research Engineer to design and evaluate agentic systems at scale. The role, based in London, focuses on context and memory management, task decomposition and communication between agents. Hands-on experience with LLMs, strong experimental rigour and strong engineering skills are expected.
Callosum is hiring a Member of Technical Staff to design and develop the runtime for long-running autonomous agents on distributed infrastructure. The role covers durable execution, distributed scheduling, debugging, observability and secure tool execution, among other areas, and requires deep expertise in Python and a systems language such as Rust, C++ or Go.
Callosum is hiring a Research Engineer specialising in evaluating agentic systems in London. The successful candidate will design benchmarks, analyse agent failures and develop evaluation and observability infrastructure. The role requires hands-on experience with LLMs, statistical rigour and strong engineering skills.
Callosum is looking for a Security Lead to define the security architecture of its APIs, orchestration systems, agentic systems and physical infrastructure. Based in London, the role also involves leading the security team and supporting sensitive deployments in sovereign, on-premises or isolated environments. Experience in infrastructure security, high-assurance environments and team management is expected.
Callosum is looking for interns interested in AI infrastructure challenges in London. Areas include high-performance systems, inference infrastructure, distributed systems, kernel development and accelerator programming. This is a general expression of interest, with no fixed internship programme or cycle.