Software Engineer, Agent Harness

About this role

Join Cursor's Agent Harness team to build core infrastructure powering AI agents across the company's coding automation platform. You'll design agent orchestration, tools, and model behavior systems while defining the default agent experience that millions of users rely on.

What you'll do

• Build and advance the agent harness framework including orchestration, tools, prompts, and execution environments
• Optimize the default Cursor agent experience (Auto model) through intelligent model selection and cost management
• Develop multi-agent coordination capabilities and expand agent platform features
• Integrate new foundational models end-to-end in collaboration with research and external partners
• Design evaluation frameworks and datasets to measure and improve agent performance
• Shape agent personality and behavior based on product requirements and user needs

What they're looking for

• Complex agentic systems and agent infrastructure development
• Production software engineering and systems design
• LLM behavior tuning and model selection strategies
• Evaluation framework and dataset design for AI systems
• Developer tools and platform building experience
• Full-stack implementation and shipping capabilities
• Understanding of emerging AI research and trends
• Cross-functional collaboration with research teams