Evolutionary Optimisation - Member of Technical Staff

About the role

This role owns Callosum’s program evolution and optimisation loop, an LLM-guided search system that iteratively generates, evaluates, and improves programs against verifiable objectives. You will develop this loop as both a reusable internal optimisation system and a research object, improving search effectiveness and pushing capabilities on complex reasoning problems. The position involves working across the full stack to co-optimise models, software, and hardware.

Responsibilities

• Develop the core program evolution loop, improving how candidates are generated, evaluated, selected, and evolved over long optimisation runs
• Design search strategies that balance exploration, exploitation, diversity, and sample efficiency across vast and irregular optimisation spaces
• Build continuous benchmarks that measure the optimiser across internal workloads and standalone problems, making improvements and regressions empirically visible
• Turn the system into reliable internal infrastructure that can optimise new verifiable domains as a reusable internal tool that other team members can scale to new problems

Required skills

• Optimisation
• Search algorithms
• Evolutionary methods
• Stochastic methods
• Combinatorial methods
• Machine learning

Benefits

• Competitive Salary
• Equity & Ownership
• Private healthcare
• Visa sponsorship
• Relocation benefits

About the Company

Callosum is the Intelligent Systems Company building the infrastructure that unifies heterogeneous compute across the full stack. They are engineers and scientists based in London, focused on building software orchestration layers that co-evolve models, workflows, and silicon.