Callosum

ML Research Engineer - Member of Technical Staff

Callosum
Apply
16 days ago
London, United KingdomSenior
H1B sponsor

Responsibilities

  • Design and run experiments across agent behavior, traces, and activations to identify failures and develop interventions that improve intelligence, cost, and reliability.
  • Research context and memory management, agent steering, task decomposition and specialization, continual learning during deployment, and inter-agent communication.
  • Build durable agent analysis and evaluation infrastructure, including observability, behavior analysis, evaluation harnesses, and auditing tools.
  • Publish evaluation results, methods, and discoveries as company assets and public research.
  • Collaborate across teams to design scalable, cost-efficient, low-latency systems and novel model or agent architectures for heterogeneous hardware.

Requirements

  • Demonstrated ability to independently conduct research by formulating open questions, designing experiments, and producing reusable results.
  • Deep hands-on experience with LLMs in agentic settings, including multi-step tasks, tool use, and long-horizon workflows.
  • Strong experimental discipline with hypotheses, controlled comparisons, ablations, and careful treatment of uncertainty and benchmark noise.
  • Strong software engineering skills and comfort writing experiment code within a substantial shared codebase.
  • Strong communication skills for translating research findings into guidance and communicating them to wider audiences.

Benefits

  • Competitive salary determined by skills and experience, equity and ownership, and private healthcare.
  • Visa sponsorship and relocation benefits are offered.
  • The role is based in person at the company's London office with provided tools, workspace, and setup.

Categories

AI Research
Callosum

About Callosum

11-50 employees
Contact me