Staff Engineer, Agent Runtime & Systems

Callosum Technologies Ltd. in London is hiring for a senior engineer to own the runtime and programming model for long-running agent systems. You will focus on durable execution, checkpointing, replay, distributed scheduling, and secure tool execution.

You’ll develop core software that makes agent workflows reliable, debuggable, and reproducible as the model and tools evolve. This high-leverage role operates across the full stack with a hands-on, problem-solving mindset.