Research Engineer, Codex

Details

The Codex team builds state-of-the-art AI systems that write code, reason about software, and act as intelligent agents for developers and non-developers. The team's mission is to advance code generation and agentic reasoning, and deploy these capabilities in products such as ChatGPT and the API, and in next-generation agentic coding tools. The team operates across research, engineering, product, and infrastructure and owns the full lifecycle of experimentation, deployment, and iteration on novel coding capabilities.

This role is based in San Francisco, CA and uses a hybrid work model (3 days in the office per week). OpenAI offers relocation assistance to new employees.

Responsibilities

• Design and run experiments to improve code generation, reasoning, and agentic behavior in Codex models.
• Develop research insights into model training, alignment, and evaluation.
• Identify and address inefficiencies across the Codex system stack, from agent behavior to LLM inference to container orchestration, and deliver high-leverage performance improvements.
• Build tooling to measure, profile, and optimize system performance at scale.
• Work across the stack to prototype new capabilities, debug complex issues, and ship improvements to production.

Requirements / Qualifications

• Strong software engineering skills; ability to rapidly prototype and turn ideas into working systems.
• Interest and experience in machine learning research, especially with large language models and code generation.
• Experience operating across ML systems and cloud infrastructure.
• Experience thinking holistically about performance trade-offs (speed, cost, user experience) and driving performance optimization efforts.
• Comfort working in highly iterative, ambiguous research and engineering environments; creativity and rigor in open-ended research problems.

Benefits

• Base salary range listed for this role: $380,000 - $460,000 per year (offers equity; total compensation may include bonuses and other components).
• Medical, dental, and vision insurance with employer contributions to Health Savings Accounts.
• Pre-tax accounts (Health FSA, Dependent Care FSA, commuter expenses).
• 401(k) retirement plan with employer match.
• Paid parental leave and paid medical/caregiver leave.
• Paid time off (flexible PTO for exempt employees; up to 15 days annually for non-exempt employees).
• 13+ paid company holidays and additional company office closures; 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 meal delivery credits as eligible.
• Relocation support for eligible employees.
• Additional taxable fringe benefits (charitable donation matching, wellness stipends) as available.

Location & Work Model

• Location: San Francisco, CA, United States.
• Hybrid work model: expected 3 days in office per week.
• Relocation assistance available for new employees.

About OpenAI

OpenAI is an AI research and deployment company focused on ensuring general-purpose AI benefits all of humanity. The company emphasizes safety, diversity of perspectives, and equal employment opportunity. Background checks and reasonable accommodations for applicants with disabilities are part of the hiring process.