Senior Software Engineer, AI (Remote UK)

Justworks is a company dedicated to helping businesses streamline their operations and HR issues. They are seeking a Senior Software Engineer to join a small team focused on building AI agents that enhance operational efficiency through advanced technology. The role involves designing and implementing core components of an agent platform, ensuring high-quality production systems, and mentoring other engineers.

Responsibilities:

• Design, build, and own core components of the agent platform, from the orchestration layer to the tool integrations connecting it to internal systems
• Build and evolve the capabilities layer: APIs, data access patterns, and service integrations for agents to execute operational workflows
• Architect the knowledge and memory infrastructure, allowing agents to retrieve the data and act across our systems
• Design and implement the trust and safety framework, including audit trails, human-in-the-loop controls, and guardrails for safe and auditable AI-driven operations
• Contribute to agent evaluation and testing infrastructure, defining how we measure accuracy, reliability, and regression across agent behaviors
• Partner directly with Operations to understand workflows, identify automation opportunities, and translate process knowledge into agent capabilities
• Mentor other engineers on the team as it grows