Member of Technical Staff – Networking & Interconnect Systems

About the role

Callosum is building the software orchestration layer that unifies heterogeneous AI accelerators. This role owns the communication boundary between accelerators, developing systems that move data efficiently across different hardware and protocols. You will shape the technical strategy to minimise latency and overhead in disaggregated workloads.

Key responsibilities

• Characterise and simplify communication paths between accelerators, tracing latency across networking, runtime, memory, and device layers.
• Develop faster data movement solutions exploring RDMA, programmable NICs, DPUs, switches and software approaches to cross‑device memory management.
• Build flexible mechanisms for transferring model state across accelerator types, including KV‑cache connectors for various parallelism strategies.
• Evaluate existing and emerging scale‑up and scale‑out fabrics to inform cluster architecture and heterogeneous accelerator communication evolution.

Required profile

• Deep understanding of networking and communication systems across protocols, hardware, memory, and software layers.
• Experience with high‑performance data movement such as RDMA, Ethernet fabrics, accelerator interconnects, or programmable networking.
• Strong systems performance instincts, able to trace bottlenecks across abstraction layers and distinguish fundamental constraints.
• Demonstrated tendency to question existing abstractions, generalise across unfamiliar technologies and simplify systems for workload requirements.

Required skills

• RDMA
• Ethernet fabrics
• Programmable NICs
• DPUs
• Switches
• Memory management across devices
• Accelerator interconnects
• Networking protocols
• Cache transfer formats
• Emerging interconnect technologies

What we offer

• Competitive salary determined by skills and experience
• Equity and ownership opportunities
• Private healthcare
• Visa sponsorship and relocation benefits
• On‑site work in our London office with full tooling and setup
• Inclusive workplace with equal opportunity commitment