Software Engineer, Agent Harness

Our mission is to automate coding. The first step in our journey is to build the best tool for professional programmers, using a combination of inventive research, design, and engineering. Our organization is very flat, and our team is small and talent dense. We particularly like people who are truth-seeking, passionate, and creative. We enjoy spirited debate, crazy ideas, and shipping code. About the Role As a Software Engineer on the Agent Harness team at SpaceXAI, you’ll build the core agent behavior and capabilities that power agent experiences across Cursor products. This spans agent orchestration, tools, guardrails, and model behavior tuning—designed as a platform that SpaceXAI engineers can extend and depend on. Your work will also define the default Cursor agent experience (”Auto”), where users trust us to make the right model choices under real-world constraints. Example projects include: Advancing the agent harness (agent loop, tools, prompts, execution environment, capabilities) used across Cursor products. This would shape and empower experiences like multi-agent coordination. Improving the default Cursor agent experience (the “Auto” model setting): making smart model choices based on user needs, model capabilities, and cost appetite. Shaping the default Cursor agent’s personality. Launching new models on Cursor end-to-end — partnering with foundational model providers and our research team on integration, evaluation, and rollout. You may be a fit if You have buil