The opportunity
About the Team The Codex Core Agent team builds the kernel of Codex. We own making the agent better, accelerating research, and making those improvements real in production for our users.
What you'll do
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 that allow agents to persist context across long-running tasks.
Optimize tokens, latency, reliability, and cost across Codex’s production fleet.
Support model rollouts, capacity planning, and the core tradeoffs between: quality, speed, and economics to manage a fleet of frontier agents at scale.
What they're looking for
- Build shared platform capabilities that unblock product teams, partner teams, and open source Codex.
- Have strong experience in distributed systems or infrastructure engineering.
- Have built systems involving containers, sandboxing, or virtualization.
- Are comfortable working across backend systems, APIs, and developer tooling.
