AI Harness Engineer

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for an AI Harness Engineer based in United Kingdom. As an AI Harness Engineer, you will build the systems and integrations that connect people with powerful local AI capabilities. You’ll work at the intersection of AI tooling, agent infrastructure, and peer-to-peer technology, helping create scalable experiences for the next generation of AI assistants. Your work will include developing reusable tools and modules, supporting diverse AI model types and sizes, and building reliable systems for non-deterministic environments. You’ll contribute to the evolution of P2P technology designed to enable local AI at scale. The role combines deep software engineering with experimentation and rapid technical exploration. You’ll join a remote, globally distributed environment where autonomy, technical curiosity, and continuous innovation are highly valued. Accountabilities Build and deliver new features and bug fixes with a strong focus on reliability, performance, and user satisfaction. Design and develop reusable tools, modules, and integrations that enable new AI capabilities across different model types and sizes. Build and maintain AI agent harnesses, including tool calling, agent loops, context management, and structured outputs. Develop evaluation frameworks and testing infrastructure for AI systems with non-deterministic behavior. Implement and evolve peer-to-