AI Agent Core Infrastructure Engineer

OpenAI; Greater London; On-site; GBP 120,000 - 180,000; Full time

Job summary

OpenAI is seeking engineers to build the infrastructure that powers Codex agents in production. You’ll design and operate sandboxed execution environments, orchestration, stateful workflows, app-server and SDK boundaries, and model rollouts.

You’ll 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.

Qualifications

• Strong experience in distributed systems and infrastructure engineering.

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.

Skills

Distributed systems

Containers & sandboxing

Backend APIs

DevOps tooling

Performance optimization

Security & isolation

Tools

Rust

CI/CD

Build systems

Job description

OpenAI is seeking engineers to build the infrastructure that powers Codex agents in production. You’ll design and operate sandboxed execution environments, orchestration, stateful workflows, app-server and SDK boundaries, and model rollouts.

You’ll 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.