Sim, the open-source platform dubbed the Figma for AI agents, is hiring a foundational full-stack engineer in San Francisco. The role owns the visual, drag-and-drop canvas used by tens of thousands to build agentic workflows without code. This hire will define the front-end architecture and developer experience for a core product in the rapidly expanding AI agent space.

The company’s approach matters because it abstracts complex agent orchestration into an intuitive visual interface. Over 70,000 developers—from startups to the U.S. Department of Defense—already use Sim to connect 1,000+ apps and LLMs. Backed by a $7M Series A from investors including Paul Graham and Perplexity, the YC X25 alum has grown its open-source project to 26,000+ GitHub stars in eight months.

On a tiny five-person team, this engineer will set performance standards and shape UX patterns for the entire platform. The job requires deep React/TypeScript expertise and a product mindset to make the canvas fast and delightful. With daily production shipping and immediate impact on a scaled product, the role offers rare ownership in a well-funded, open-source AI infrastructure play.