Senior Staff Backend Software Engineer, API Platform

About the Team Our team brings OpenAI’s most capable technology to the world through our developer platform: the OpenAI API. As the leading AI development platform, our API is used by millions of developers and the majority of enterprises around the world, and powers the majority of AI applications that you may use on a daily basis. Most recently, we’ve released gpt-5, gpt-realtime, Responses API, Agents SDK, and many other products and features. About the Role We are looking for a software engineer to own the design of our APIs. Our API is our product, and as such we treat its design and development with care and intentionality. Every endpoint, every field name, and every enum value is a product interface that we want to design well. We are looking for engineers who not only love building APIs, but who will also sweat the details around API design and have a discerning taste for well designed API experience. You will play a major role in shaping the future roadmap of the OpenAI API – by both building and designing it. In this role, you will: Design and build products that we launch in API – extending existing endpoints, adding new endpoints, or rethinking our entire API suite. Play a major role in our API Review process – working with all other teams to ensure our APIs meet our design standard. Collaborate closely with the rest of the API team, our Developer Experience team, and our GTM team to make our APIs the best in the world. You might thrive in this role if you: Appreciate taste in API design – you believe there are well designed APIs and poorly designed APIs Can thrive and operate independently in a fast-paced environment with ambiguous requirements and goals Love building for other developers, and thrive on feedback from opinionated users Are an engineer at heart, but are willing to lean into product decisions. Think of APIs as ladders . Title note: At OpenAI, research and engineering hires share the internal title Member of Technical Staff . We use Senior Staff externally to signal the depth of experience, ownership, and technical leadership expected for this role. 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. In addition, job duties require access to secure and protected information technology systems and related data security obligations. To notify OpenAI that you believe this job posting is non-compliant, please submit a report through this form . No response will be provided to inquiries unrelated to job posting compliance. We are committed to providing reasonable accommodations to applicants with disabilities, and requests can be made via this link . OpenAI Global Applicant Privacy Policy At OpenAI, we believe artificial intelligence has the potential to help people solve immense global challenges, and we want the upside of AI to be widely shared. Join us in shaping the future of technology.