AI Systems Engineer, Codex Agents

Responsibilities

• Design and build the core agent harness and execution loops that enable Codex agents to interpret model outputs and complete complex, long-horizon tasks safely.
• Build sandboxing, isolation, orchestration, and workflow infrastructure for agents operating in real development environments.
• Develop evaluation, experimentation, and debugging systems to distinguish between harness, model, and inference issues.
• Run ablations across prompts, tool-use strategies, and harness behavior to improve reliability, latency, and cost.
• Improve observability and diagnostics across the agent stack, from backend systems to GPUs and fleet capacity.
• Work closely with research to make the harness trainable and useful for improving frontier agentic models.

Requirements

• Experience building or operating production distributed systems, infrastructure, or ML systems.
• Hands-on experience with LLM applications, coding agents, or model deployment.
• Proficiency in Rust or Python.
• Experience with sandboxing, virtualization, or cloud platforms.
• Ability to debug complex issues across the full stack, from low-level systems to model behavior.

Preferred Qualifications

• Deep experience with low-level platform engineering, kernels, or runtimes.
• Background in inference optimization, GPU systems, or performance engineering.
• Experience with model evaluations or post-training feedback loops.
• Experience building production infrastructure used by large-scale engineering teams.

Benefits

• Competitive salary ($230K – $385K) and generous equity.
• Comprehensive medical, dental, and vision insurance.
• 401(k) retirement plan with employer match.
• Paid parental leave and flexible PTO.
• Daily meals in the office and mental health support.
• Annual learning and development stipend.

About the Company

OpenAI is an AI research and deployment company dedicated to ensuring that general-purpose artificial intelligence benefits all of humanity. We push the boundaries of AI capabilities and seek to safely deploy them to the world through our products.