About the RoleAs a Performance & Systems Engineer on the Codex team, you will be responsible for whole-system optimization across a complex, evolving stack. Codex spans LLM inference, cloud orchestration, agentic work management, and multiple product surfaces. Your job will be to identify and land high-leverage changes-across infrastructure, modeling, and product layers-that make Codex agents significantly faster and cheaper to serve.
We're looking for generalists who thrive in ambiguity and love chasing performance bottlenecks to ground. This is a high-ownership role where your work will directly improve the experience of millions of users.
This role is based in San Francisco, CA. We use a hybrid work model of 3 days in the office per week and offer relocation assistance to new employees.
In this role, you will:- Hunt down and address inefficiencies across the Codex system stack, from agent behavior to LLM inference to container orchestration, and beyond.
- Build tooling to measure, profile, and optimize system performance at scale.
- Collaborate with researchers and engineers to land high-ROI changes that improve latency and cost.
You might thrive in this role if you:- Have experience operating across both ML systems and cloud infrastructure.
- Enjoy diving into messy, ambiguous problems and emerging with clear wins.
- Think holistically about performance, balancing speed, cost, and user experience.
