Software Engineer, Identity

About Mercor Mercor's mission is to organize human intelligence to power the AI economy. We're a leading AI data company, building the layer between human expertise and frontier models. Millions of domain experts on the platform are paid over $4 million per day to train frontier AI models. Mercor's APEX benchmark family measures AI's real-world impact on professional work. Mercor Enterprise brings this same infrastructure to Fortune 500 companies: helping companies capture how their best people actually work, translating that expertise directly back into agents. Mercor is creating a new category of work where expertise powers AI advancement. Achieving this requires an ambitious, fast-paced and deeply committed team. You’ll work alongside researchers, operators, and AI companies at the forefront of shaping the systems that are redefining society. Mercor is a profitable Series C company valued at $10 billion. We work in-person five days a week in our San Francisco, NYC, or London offices. Why This Role We build systems that make billions of authorization decisions a week for hundreds of thousands of users, most of them contractors and experts rather than employees. A typical company's IdP models a few thousand employees. Ours models a global expert network where membership turns over constantly, every client engagement needs its own isolation boundary, and a wrong permission can expose a frontier lab's data. The team is small, led by one of Mercor's earliest engineers, and operates with a high degree of ownership. There's no spec handed to you: you own the product scope and direction, with the team weighing in on prioritization and technical detail. Examples of What We Build IAM-Service is our authorization service for first-party surfaces. It sits in the hot path of every request across our own products, backed by SpiceDB , an open-source implementation of Google's Zanzibar. We model access as relationships rather than roles (ReBAC instead of RBAC), which is what let