Software Engineer, API Frontiers

About the Team API Frontiers turns OpenAI’s frontier models into production APIs that developers can use to build reliable products and agents. We own the core path connecting models to developers through the Responses API, with a focus on safety, reliability, and speed. Working closely with Research, Safety, Codex, and other API teams, we bring new model capabilities into production and improve them through developer feedback. About the Role We are looking for 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. The work combines distributed systems engineering with product judgment: designing useful developer interfaces, managing staged rollouts, and following production issues through to durable fixes. In this role, you will: • 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. Your background might look something like: • 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. About OpenAI OpenAI is an AI research and deployment company dedicated to ensuring that general-purpose artificial intelligence benefits all of humanity. We push the boundaries of the capabilities of AI systems and seek to safely deploy them to the world through our products. AI is an extremely powerful tool that must be created with safety and human needs at its core, and to achieve our mission, we must encompass and value the many different perspectives, voices, and experiences that form the full spectrum of humanity. We are an equal opportunity employer, and we do not discriminate on the basis of race, religion, color, national origin, sex, sexual orientation, age, veteran status, disability, genetic information, or other applicable legally protected characteristic. For additional information, please see OpenAI’s Affirmative Action and Equal Employment Opportunity Policy Statement. Background checks for applicants will be administered in accordance with applicable law, and qualified applicants with arrest or conviction records will be considered for employment consistent with those laws, including the San Francisco Fair Chance Ordinance, the Los Angeles County Fair Chance Ordinance for Employers, and the California Fair Chance Act, for US-based candidates. For unincorporated Los Angeles County workers: we reasonably believe that criminal history may have a direct, adverse and negative relationship with the following job duties, potentially resulting in the withdrawal of a conditional offer of employment: protect computer hardware entrusted to you from theft, loss or damage; return all computer hardware in your possession (including the data contained therein) upon termination of employment or end of assignment; and maintain the confidentiality of proprietary, confidential, and non-public information. 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