Senior Software Engineer, AI (remote - Spain)

Justworks is a company that provides HR solutions for businesses, aiming to help them focus on their core operations. They are seeking a Senior Software Engineer to join a small team focused on building AI agents that enhance operational workflows and transform business processes at scale.

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

Requirements:

• Holds at least 5 years of backend systems engineering experience
• Experience with AI/LLM agent platform development
• API design & system integration experience
• Must be product thinking
• Must have experience with owning projects and be comfortable with self-direction