Applied AI Engineer, Codex Core Agent

OpenAI is hiring an Applied AI Engineer to work on the Codex Core Agent — the reasoning and tool-use engine that powers autonomous coding workflows. You will build the systems that let models plan, write, execute, and verify code across real software projects. You will design agent loops and tool interfaces, improve how the agent handles long-horizon tasks and recovers from errors, and develop evaluations that measure real-world coding performance. Expect to move fluidly between prompting, orchestration, backend engineering, and model behavior analysis. This role sits at the center of one of OpenAI's fastest-moving product areas. If you are excited about building reliable AI agents that ship code for millions of developers, this is a chance to define what agentic software engineering looks like.