Senior Backend Engineer, Frontier AI APIs

OpenAI; New York, San Francisco (NY, CA); On-site; USD 180,000 - 240,000; Full time

Job summary

OpenAI is seeking a backend software engineer to build and operate the services behind the Responses API. You will shape API behavior, bring new capabilities from research into production, and make long-running agent workflows dependable and fast.

This role combines distributed systems engineering with product judgment—designing useful developer interfaces, managing staged rollouts, and driving observability and performance improvements in production environments.

Qualifications

• 5+ years of experience building and operating backend services or developer-facing APIs in production.
• Strong software engineering fundamentals, with practical knowledge of distributed systems, concurrency, and asynchronous execution.
• Ability to diagnose production failures and performance bottlenecks using observability data and profiling.
• Product judgment and developer empathy, with a track record of translating complex capabilities into clear, dependable APIs.
• Experience taking ownership of ambiguous technical problems, from defining an approach through shipping and improving the result.
• Clear communication and effective collaboration across engineering, research, product, and safety disciplines.
• Experience with Rust, streaming protocols or WebSockets, or long-running workflow systems is a plus.

Responsibilities

• Design, build, and operate APIs and backend services that bring frontier model capabilities to developers.
• Partner with Research, Safety, Codex, and API teams to define API behavior and deliver safe, staged launches.
• Build API capabilities for agent workflows, including task delegation, context sharing, and parallel execution.
• Strengthen long-running request reliability across timeouts, cancellation, streaming, and background execution.
• Improve request-processing performance and tail latency through profiling, efficient systems code, and persistent connections.
• Turn developer feedback and production failures into better observability, diagnostics, and lasting product improvements.

Skills

Backend development

Distributed systems

Rust

Performance profiling

Observability

APIs

Tools

WebSockets

Job description

OpenAI is seeking a backend software engineer to build and operate the services behind the Responses API. You will shape API behavior, bring new capabilities from research into production, and make long-running agent workflows dependable and fast.

This role combines distributed systems engineering with product judgment—designing useful developer interfaces, managing staged rollouts, and driving observability and performance improvements in production environments.