Research Engineer, Codex

Skills

About the Role

You will improve the capabilities, reliability, and product fit of agentic models. You might own a research direction, build infrastructure for large training runs, create evals that reveal model failures, or drive a capability from idea through experimentation, integration, and launch. You'll work with researchers, engineers, product, infrastructure, and safety partners to decide what goes into major model runs and ship improvements.

Requirements

• Strong technical fundamentals in machine learning, software engineering, systems, statistics, or a related field
• Hands-on experience with LLMs, RL, RLHF/RLAIF, post-training, evals, graders, synthetic data, model training, or coding agents
• Comfort with open-ended problems combining research and engineering
• Ability to move from a vague problem to a concrete experiment
• Ability to work across research, product, infrastructure, data, evals, and safety

Responsibilities

• Design and run experiments that improve agentic model behavior
• Own end-to-end improvements to the post-training stack including RL, data pipelines, graders, reward signals, and evals
• Build evals and environments that expose model failures and turn them into training data or fixes
• Partner with product teams to translate product signal into model improvements
• Work on early-training and alignment interventions such as data mixtures, objectives, and synthetic data
• Help decide which integrations and fixes go into major model runs
• Improve large-scale training machinery: velocity, reliability, observability, reproducibility, cost, latency
• Take on cross-functional projects touching model training and the production agent harness
• Debug hard failures in shipped or near-shipped models

Benefits

• Equity
• Medical, dental, and vision insurance with employer HSA contributions
• Pre-tax Health FSA, Dependent Care FSA, and commuter accounts
• 401(k) with employer match
• Paid parental leave (up to 24 weeks for birth parents, 20 weeks for non-birthing parents)
• Paid medical and caregiver leave (up to 8 weeks)
• Flexible PTO for exempt employees; up to 15 days for non-exempt
• 13+ paid company holidays and company office closures
• Paid sick or safe time
• 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
• Relocation support for eligible employees
• Charitable donation matching and wellness stipends