Applied AI Engineer, Codex Core Agent
AI summary of the role
This role is on the Codex Core Agent team, building the kernel of Codex—the agent that turns models into useful behavior in production.
What you’ll do
- Design and iterate on agent behaviors across real-world coding tasks and long-horizon workflows.
- Work closely with research to develop and run evals to measure agent performance, regressions, failure modes, and edge cases.
- Improve performance through prompting, tool-use strategies, context construction, and model-facing experimentation.
- Analyze failures in production and systematically improve robustness and reliability.
What you’ll bring
- Experience building or shipping machine learning or LLM-powered products.
- Strong in Python and comfortable with modern ML tooling.
- Experience with model evaluation, fine-tuning, or prompt design.
- Think in terms of systems and user outcomes, not just model metrics.
Technologies
Python · LLM · Codex · agent frameworks · tool-using LLM systems · code generation models · prompt design · fine-tuning · model evaluation
About OpenAI
Builds frontier AI models (GPT series) and ships them as ChatGPT consumer/enterprise products plus a developer API for the broader AI ecosystem.
Private Late
Source and classification
Internal deployment & tooling · Evidence for this classification:
About the Team The Codex Core Agent team builds the kernel of Codex. We own making the agent better, accelerating research, and making those improvements real in production for our users. That means working across the systems that make Codex actually function as an agent in the real world: the production performance envelope around tokens, latency, reliability, cost, and capacity; the core execution loop and interfaces that turn models into useful behavior; the shared infrastructure that enables other teams to build on Codex; and the feedback loops that turn real-world usage into better models and better agent behavior over time. About the Role We’re looking for applied AI engineers to help bring Codex agents from impressive demos to dependable tools. This role is about improving agent performance on real software engineering tasks and closing the gap between research capability and
More from the job description
About the Team The Codex Core Agent team builds the kernel of Codex. We own making the agent better, accelerating research, and making those improvements real in production for our users. That means working across the systems that make Codex actually function as an agent in the real world: the production performance envelope around tokens, latency, reliability, cost, and capacity; the core execution loop and interfaces that turn models into useful behavior; the shared infrastructure that enables other teams to build on Codex; and the feedback loops that turn real-world usage into better models and better agent behavior over time. About the Role We’re looking for applied AI engineers to help bring Codex agents from impressive demos to dependable tools. This role is about improving agent performance on real software engineering tasks and closing the gap between research capability and real-world usefulness. You’ll work closely with research, infrastructure, and product to ensure agents are not just powerful, but useful, steerable, and reliable in practice. The job is not only to improve model behavior in isolation, but to turn those improvements into measurable gains in solve rate, usefulness, and economic value for users. What You’ll Do Design and iterate on agent behaviors across real-world coding tasks and long-horizon workflows. Work closely with research to develop a [... source excerpt omitted ...] gressions, failure modes, and edge cases. Improve performance through prompting, tool-use strategies, context construction, and model-facing experimentation. Analyze failures in production and systematically improve robustness and reliability. Build feedback loops and data systems that get better real-task data into evaluation and research. Work with product teams to shape user-facing agent experiences and the interfaces the agent depends on. Help define what “good” looks like for agents completing complex tasks end-to-end. You Might Be a Good Fit If You Have experience building or shipping machine learning or LLM-powered products. Are strong in Python and comfortable with [... source excerpt omitted ...] Experience with agent frameworks or tool-using LLM systems. Research experiencewith code generation models or developer tooling. Experience working with large, messy datasets or production logs. 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 f
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