Software Engineer, Codex Core Agents
📍 New York City, United States
📍 San Francisco, United States
📍 Seattle, United States
Used Tools & Technologies
LLMRequired Skills & Competences
Tag name is followed by "@" symbol and proficiency level value.
About proficiency levels:
- 1-2 — basic awareness. Minimal hands-on experience, and a rudimentary understanding of the technology's purpose;
- 3-6 — daily use. Comfortable and regular usage, capable of handling common tasks and challenges related to the technology;
- 7-9 — you are an expert, you can teach others, you know all the pitfalls and tricks;
- 10 — exceptional knowledge, comprehensive understanding, and adeptness in all aspects of the technology, including advanced problem-solving. Think twice before claiming or demanding such level.
Security @ 3
CI/CD @ 3
Distributed Systems @ 3
Debugging @ 3
API @ 3
Codex @ 3
AI @ 3
- 1-2 — basic awareness. Minimal hands-on experience, and a rudimentary understanding of the technology's purpose;
- 3-6 — daily use. Comfortable and regular usage, capable of handling common tasks and challenges related to the technology;
- 7-9 — you are an expert, you can teach others, you know all the pitfalls and tricks;
- 10 — exceptional knowledge, comprehensive understanding, and adeptness in all aspects of the technology, including advanced problem-solving. Think twice before claiming or demanding such level.
Details
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.
That means working across the systems that make Codex actually function as an agent in the real world: the production performance envelope around tokens, latency, reliability, cost, and capacity; the core execution loop and interfaces that turn models into useful behavior; the shared infrastructure that enables other teams to build on Codex; and the feedback loops that turn real-world usage into better models and better agent behavior over time.
About the Role
Were looking for engineers to build the infrastructure that powers Codex agents in production. This role focuses on the systems that let models safely execute code, interact with tools, complete long-running tasks, and operate reliably and efficiently at scale.
Youll design and operate the infrastructure behind sandboxed execution, orchestration, stateful workflows, app-server and SDK boundaries, and model rollouts. Youll work at the intersection of distributed systems, developer tooling, and AI, building primitives that make Codex faster, safer, more reliable, and easier for the rest of the organization to build on.
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 the core tradeoffs between quality, speed, and economics to manage 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.
- Comfortable working across backend systems, APIs, and developer tooling.
- Care deeply about system reliability, performance, and security.
- Enjoy working on ambiguous, zero-to-one problems.
- Desire to help build the systems that turn model capability into a dependable software engineering agent.
Bonus Points
- Experience with code execution platforms, CI/CD systems, or build systems.
- 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.
Benefits
- Medical, dental, and vision insurance with employer contributions to Health Savings Accounts (where applicable).
- Pre-tax accounts for Health FSA, Dependent Care FSA, and commuter expenses.
- 401(k) retirement plan with employer match.
- Paid parental leave (up to 24 weeks for birth parents and 20 weeks for non-birthing parents); paid medical and caregiver leave (up to 8 weeks).
- Paid time off: flexible PTO for exempt employees and up to 15 days annually for non-exempt employees.
- 13+ paid company holidays and multiple coordinated company office closures.
- Mental health and wellness support.
- Employer-paid basic life and disability coverage.
- Annual learning and development stipend.
- Daily meals in offices and meal delivery credits as eligible.
- Relocation support for eligible employees.
- Additional taxable fringe benefits such as charitable donation matching and wellness stipends.
About OpenAI
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 the capabilities of AI systems and seek to safely deploy them to the world through our products. AI is an extremely powerful tool that must be created with safety and human needs at its core. OpenAI is an equal opportunity employer and provides reasonable accommodations to applicants with disabilities.