Software Engineer, Codex Core Agents

Details

The Codex Core Agent team builds the kernel of Codex, improving the agent, accelerating research, and bringing those improvements to production. The team works across production performance, the core execution loop, shared infrastructure, and feedback loops that improve models and agent behavior over time.

The role involves building infrastructure that powers Codex agents in production, including systems that allow models to safely execute code, interact with tools, complete long-running tasks, and operate reliably and efficiently at scale. You will work at the intersection of distributed systems, developer tooling, and AI, building primitives for sandboxed execution, orchestration, stateful workflows, app-server and SDK boundaries, and model rollouts.

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 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 tradeoffs between quality, speed, and economics for a fleet of frontier agents at scale.
• Build shared platform capabilities that unblock product teams, 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.
• Strong focus on system reliability, performance, and security.
• Ability to work on ambiguous, zero-to-one problems.
• Interest in building systems that turn model capability into a dependable software engineering agent.

Bonus Points

• Experience with code execution platforms, CI/CD systems, or build systems.
• Experience coding in Rust.
• Familiarity with LLMs, agents, or tool-use frameworks.
• Background in security engineering or isolation systems.
• Experience building developer platforms, IDE tooling, or open source infrastructure.

About OpenAI

OpenAI is an AI research and deployment company dedicated to ensuring that general-purpose artificial intelligence benefits all of humanity. OpenAI is an equal opportunity employer and does not discriminate on the basis of legally protected characteristics. Background checks and reasonable accommodations are handled in accordance with applicable laws.

Benefits

• Base salary of $230,000–$385,000 per year, plus equity.
• Medical, dental, and vision insurance, with employer contributions to Health Savings Accounts.
• Pre-tax accounts for health, dependent care, and commuter expenses.
• 401(k) retirement plan with employer match.
• Paid parental, medical, and caregiver leave.
• Paid time off, company holidays, office closures, and paid sick or safe time as required by law.
• Mental health and wellness support.
• Employer-paid basic life and disability coverage.
• Annual learning and development stipend.
• Daily meals in offices and eligible meal delivery credits.
• Relocation support for eligible employees.
• Potential additional taxable fringe benefits, including charitable donation matching and wellness stipends.