Software Engineer, Codex Core Agents
San Francisco • FullTime
Posted 5mo ago
About the job
We are seeking engineers to build the core infrastructure that powers Codex agents in production. This role involves designing and operating systems for sandboxed execution, orchestration, stateful workflows, and reliable, efficient operation at scale. You will work at the intersection of distributed systems, developer tooling, and AI, building primitives that enhance the speed, safety, reliability, and ease of use of Codex for the organization.
Responsibilities
- Design and build execution environments for AI agents, including sandboxing, isolation, and reproducibility.
- Develop systems for agent orchestration across multi-step, tool-using workflows.
- Build infrastructure for running, testing, and debugging code generated by models.
- Create state and memory systems for agents to persist context across long-running tasks.
- Optimize tokens, latency, reliability, and cost for Codex's production fleet.
- Support model rollouts, capacity planning, and manage trade-offs for a fleet of frontier agents.
- Build shared platform capabilities to unblock product and partner teams, and open source Codex.
Requirements
- Strong experience in distributed systems or infrastructure engineering.
- Experience building systems involving containers, sandboxing, or virtualization.
- Comfort working across backend systems, APIs, and developer tooling.
- Deep care for system reliability, performance, and security.
- Enjoy working on ambiguous, zero-to-one problems.
- Desire to build systems that turn model capability into a dependable software engineering agent.