Principal Software Engineer, Full Stack — Codex
OpenAI is hiring a Principal Software Engineer, Full Stack — Codex in San Francisco, United States. It pays $459k-$536k a year and Level rates it ; you can apply on OpenAI.
Level's read on this job
- Level rates this software engineer role Works on AI ●●●○: the daily work is on AI products, without building the model.
- The listed pay starts 175% above the typical software engineer posting on Level.
- Tools and skills the posting cites include prompt engineering, AI agents and AI research.
- Level classifies it as a lead role.
- Level lists 819 other open roles at OpenAI.
AI in this role
About the Role
We’re hiring a Principal Software Engineer to help define and build the next generation of AI-powered software development workflows.
“Full stack” in this role extends well beyond traditional frontend and backend development. You will set technical direction and lead major product initiatives spanning user interfaces, developer tooling, workflow orchestration, agent and prompt design, backend systems, and cloud infrastructure.
This is a highly product-oriented technical leadership role. You will identify the highest-leverage opportunities across the software development lifecycle, turn ambiguous user and technical problems into durable product and system strategies, and lead execution across multiple engineers and partner teams. Your work will shape both the architecture of Codex and how developers around the world design, write, review, test, and maintain software.
You will operate as a senior individual contributor: remaining deeply involved in design and implementation while raising the technical judgment, execution quality, and ambition of the broader team.
In this role, you will
Set the technical and product direction for significant areas of Codex, translating an evolving product vision into scalable architectures and an actionable engineering strategy.
Lead complex, multi-quarter initiatives spanning client applications, backend services, agent systems, cloud infrastructure, and developer tooling.
Design AI-powered workflows that generalize across languages, codebases, development environments, and organizations while remaining intuitive, reliable, and safe.
Make high-consequence architectural decisions under ambiguity, balancing rapid product learning with long-term system quality and adaptability.
Identify opportunities that cut across existing team or product boundaries, align stakeholders around a direction, and drive the work from exploration through launch and iteration.
Partner closely with product, design, research, infrastructure, security, and go-to-market teams to turn emerging model capabilities and developer needs into coherent product experiences.
Work directly with developers, open-source maintainers, startups, and large enterprises to uncover unmet needs and distinguish foundational opportunities from incremental improvements.
Establish patterns and standards for reliability, observability, performance, experimentation, and evaluation across AI-powered developer workflows.
Serve as a technical multiplier by reviewing critical designs, mentoring engineers, improving engineering practices, and helping the team navigate its hardest product and technical decisions.
Contribute directly to implementation, particularly where the problem is novel, technically demanding, or requires connecting multiple layers of the product.
You might thrive in this role if you
Have led the design and delivery of technically complex, user-facing systems with impact extending beyond a single feature or team.
Combine deep software-engineering expertise with exceptional product judgment and can move fluently across product interfaces, distributed systems, infrastructure, and developer tooling.
Have a track record of creating clarity in ambiguous problem spaces, setting a compelling technical direction, and bringing multiple teams or disciplines along with you.
Remain hands-on while increasing the effectiveness of other engineers through architecture, mentorship, decision-making, and technical leadership.
Understand modern software-development workflows deeply and can recognize where AI agents require fundamentally new interaction and system designs.
Have experience building or operating AI-powered products and understand the challenges created by nondeterminism, evaluation, latency, reliability, safety, and rapidly evolving model capabilities.
Make thoughtful tradeoffs between speed, product learning, technical quality, and long-term leverage.
Develop strong perspectives from user evidence while remaining willing to revise those perspectives as technology and user behavior evolve.
Communicate clearly across engineering, product, design, research, and executive audiences, especially when decisions involve substantial uncertainty or organizational complexity.
Are energized by defining a problem as much as solving it—and by creating the technical and organizational conditions for others to deliver excellent work.
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.
How we rate this
Principal Software Engineer, Full Stack — Codex at OpenAI rates 71 out of 100 for how much of the daily work is AI. That makes it Works on AI (AI Level 3 of 4). The level is about AI in the job, not seniority.
Works on AI. The daily work is on AI products, without building the model.
- ●●●● Builds AI80 to 100
- ●●●○ Works on AI60 to 79
- ●●○○ Uses AI40 to 59
- ●○○○ Little AI0 to 39
Levels come from how often the tools, models and workflows of the role are named in the posting itself. Read the description and count the AI tools, models and workflows it names.
Prepare for this job
Built from this posting and from similar jobs on Level.
Skills and AI tools this role asks for
Also common in software engineer jobs at this level
Pay
- This job starts at
- $459k
- Typical software engineer job
- $167k
This posting starts 175% above the typical software engineer job. See software engineer jobs
Questions you could be asked
- How do you structure and test a prompt to get consistent output from a language model?
- How do you decide when an AI agent can act on its own versus asking for approval first?
- Tell me about a research question you investigated. What did you find?
- Describe a typical day in a role like this one: which parts run through AI directly?
- If you removed AI from this role, what would be left, and how do you decide what still needs a human?
Adapt your resume
- List these exact terms on your resume: Prompt engineering, AI agents, and AI Research. An applicant tracking system matches the wording, not the idea.
- Attach one line of real, concrete experience to at least one of them. A tool named with nothing behind it rarely survives a human read.
- Show where AI is part of your daily process, not a one-off project. This role expects it to be a running habit.
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