OpenAI
AI Systems Engineer, Codex Agents
About this role
Build production-grade AI agent systems at OpenAI that translate model capabilities into reliable, real-world actions. You'll design the core agent harness, execution infrastructure, and evaluation frameworks while working across the full stack from low-level systems to model behavior and GPU fleet optimization.
What you'll do
- Design and build agent harness and execution loops for tool use, code execution, and long-horizon task completion
- Develop sandboxing, orchestration, and state management infrastructure for agents in real development environments
- Create evaluation and debugging systems to isolate issues across harness, model, inference, and product layers
- Run ablations on prompts, model interfaces, and harness behavior to improve solve rate, reliability, latency, and cost
- Improve observability, profiling, and diagnostics across the agent stack from backend to GPU fleet
- Collaborate with research to make the harness trainable and useful for improving frontier models
What they're looking for
- Distributed systems and production infrastructure
- Rust systems programming
- Python and API development
- LLM applications and coding agents
- Debugging and troubleshooting across system layers
- Sandboxing, virtualization, and isolation technologies
- Performance engineering and profiling
- Inference optimization and GPU systems
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OpenAI
OpenAI builds AI infrastructure and products, including large-scale data center campuses for AI computing and generative AI applications for enterprise customers. The company is hiring civil engineers, project engineers, electrical design engineers, data center R&D engineers, and AI deployment engineers to expand its infrastructure capabilities and help customers deploy AI solutions.
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