OpenAI

AI Systems Engineer, Codex Agents

OpenAIToday
Location

San Francisco

Type

Full Time

Salary

USD 230,000 – 385,000

Level

Senior

Role

AI Systems Engineer

Posted

May 15, 2026

Full TimeSenior

The role

Summary

OpenAI is seeking a highly skilled AI Systems Engineer for the Codex Core Agents team, focusing on building advanced agent harness systems that transform AI model capabilities into actionable real-world solutions. The ideal candidate will work across multiple technical layers, from low-level systems to ML workflows, to enhance the reliability, safety, and performance of AI agents.

What you'll do

Agent Harness Development: Design and build the core agent execution loop enabling Codex agents to interpret model outputs, use tools, execute code, and complete complex tasks safely
Infrastructure Engineering: Develop sandboxing, isolation, orchestration, and workflow infrastructure for agents operating in real development environments
Performance Optimization: Run ablations and experiments to improve agent solve rate, reliability, latency, and cost across model interfaces and harness behaviors
Observability Enhancement: Improve diagnostics, profiling, and observability across the entire agent technology stack from backend systems to GPU inference
Collaborative Research Integration: Work closely with research teams to make the agent harness trainable, measurable, and useful for improving frontier agentic models

What we look for

Technical

Systems ProgrammingAdvanced experience with Rust systems code, distributed systems, and low-level infrastructure development
Machine Learning InfrastructureHands-on experience with LLM applications, model deployment, inference optimization, and developer platforms
Cloud and Runtime TechnologiesProficiency in cloud platforms, virtualization, sandboxing, and runtime performance optimization

Education

Advanced Technical DegreeBachelor's or Master's degree in Computer Science, Software Engineering, or related technical discipline preferred

Experience

Production SystemsDemonstrated experience building and operating production systems in distributed computing, developer tooling, or ML infrastructure
Multi-Layer Technical ExpertiseProven ability to work across technical layers including systems code, configuration layers, APIs, orchestration, and runtime constraints

Skills

Required skills

Rust ProgrammingStrong systems-level programming skills in Rust
PythonProficiency in Python for configuration and scripting
Distributed SystemsDeep understanding of distributed computing principles

Nice to have

Compiler DesignBackground or experience in compilers, kernels, and runtime systems
GPU SystemsKnowledge of GPU system optimization and performance engineering
Open Source DevelopmentExperience contributing to infrastructure or developer platform open-source projects

Compensation & benefits

Salary

USD 230,000 – 385,000 (annual)

Stock options

Available

Benefits

Equity Compensation

Stock options offering potential additional financial upside

Cutting-Edge Work

Opportunity to work at the forefront of AI systems engineering

Research Collaboration

Close interaction with world-class AI research teams

Interview process

  1. 1
    Initial Screening — Technical resume review and initial recruiter conversation
  2. 2
    Technical Interview — Detailed technical assessment of systems engineering and ML infrastructure skills
  3. 3
    Systems Design Challenge — In-depth evaluation of candidate's ability to design complex AI agent systems
  4. 4
    Final Team Interview — Comprehensive discussion with Codex Core Agents team members
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OpenAI

OpenAI

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OpenAI is an American artificial intelligence research organization developing advanced AI models like GPT. Focused on ensuring AI benefits humanity, it creates tools for natural language processing and generative AI applications.

San Francisco, California, United StatesFounded 2015openai.com

Tech Stack

Languages
RustPython
Frameworks
ML InfrastructureAgent Orchestration
Databases
Performance Databases
Tools
GPU Optimization ToolsSandboxing Tools
Other
AI Model Evaluation

Interview Guides

5 guides available for OpenAI

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