2 days ago
London, United KingdomSenior
Responsibilities
- Extend simulators to predict heterogeneous compute performance from individual accelerators through multi-rack deployments.
- Model networking, memory, and execution behavior across alternative system architectures and configurations.
- Develop profiling, tracing, instrumentation, and workload-capture tools to inform and validate simulation models.
- Extend simulation environments for experimentation and automated optimization of systems and algorithms.
- Characterize emerging accelerator architectures and translate hardware measurements into predictive system-level performance models.
Requirements
- Strong experience in systems simulation, performance modelling, or performance-critical systems software.
- Deep understanding of computer architecture, distributed systems, or high-performance computing.
- Familiarity with profiling, tracing, instrumentation, and computational workload characterization.
- Strong systems programming experience, ideally including C++ or Rust.
- Ability to reason about modelling accuracy, abstraction, simulation fidelity, and computational cost trade-offs.
Benefits
- Competitive salary determined by skills and experience.
- Equity and ownership.
- Private healthcare.
- Visa sponsorship and relocation benefits.
- In-person work at the London office with provided tools, workspace, and setup.
About Callosum
Callosum builds AI infrastructure that unifies heterogeneous compute—software and systems to orchestrate diverse accelerators and the physical clusters they run on—for organizations training and serving models. The privately held company was founded in 2025 and is headquartered in London. It focuses on designing, deploying, and operating mixed-hardware compute fleets across sites and vendors, and raised a seed round in 2026.