Job description

About Patronus AI Patronus AI is a frontier lab developing simulation research and infrastructure to accelerate progress toward human-aligned AGI. We are on a mission to simulate all of the world’s intelligence. We are the team behind some of the earliest and most influential research in AI evaluation like FinanceBench , Lynx , SimpleSafetyTests , CopyrightCatcher , Humanity’s Last Exam , and more. We are formerly AI researchers and engineers from companies like Meta AI, Amazon AGI, and Google. Our customers include foundation model labs and Fortune 500 enterprises like Adobe. We are backed by top-tier investors like Lightspeed Venture Partners, Notable Capital, Stanford University, Noam Brown, Gokul Rajaram, and more. Responsibilities As a Researcher at Patronus AI, you will own and drive foundational research that defines how agentic AI systems are trained, evaluated, and improved. You will work at the intersection of reinforcement learning, simulations, and scalable oversight, building systems that directly influence how frontier models are developed, stress-tested, and deployed. This is a highly autonomous role. You will tackle open-ended research questions surrounding agent simulations and translate them into rigorous experiments, benchmarks, environments, and production systems. You will work across areas including reward design, tool simulations, agent cognition, behavior analysis, and scalable oversight, helping shape the industry standard for robust, high-quality environments. Your work will inform how frontier labs design, train, evaluate, and improve the next generation of agents for complex, long-horizon tasks, advancing our path toward safe, human-aligned general intelligence. In this role, you will: Own ambitious research projects end-to-end , from identifying and formulating open-ended problems through experiment design, execution, analysis, and production impact. Advance research in agent simulation, reinforcement learning, and scalable oversight , including agent cognition, behavior analysis, reward design, and new training methods. Design state-of-the-art simulation and RL environments for training and evaluating frontier agents, spanning tools and actions, observations and state, trajectories, curricula, and reward systems. Train models and experiment with post-training algorithms , including GRPO and SFT. Run ablations with open source models and understand the impact of distillation, COT reasoning, sparse and dense rewards and hyperparameters. Develop methods to understand and improve agent behavior across complex, long-horizon tasks, including reasoning, planning, adaptation, generalization, and reward hacking. Run rigorous experiments and turn findings into measurable outcomes , including new techniques, benchmarks, datasets, environments, platform capabilities, and research publications. Build high-quality, reproducible research systems , writing production-level code and partnering closely with engineering and product to translate research into real-world systems. Contribute to Patronus AI’s research direction and thought leadership , staying at the frontier of the field, collaborating with the research community, and publishing or open sourcing our work. Qualifications "The number one qualification to succeed in this machine learning course is gumption” - John Lafferty, CS Professor at Yale Above all, we look for an eagerness to learn, passion for research, creativity in problem solving and a proactive mindset. You are a great fit if you have a background in the following: An MS or PhD in Computer Science, Machine Learning, Statistics, Mathematics, or a related quantitative field. Experience conducting independent research in reinforcement learning, NLP, agentic systems, evaluation, alignment, or related areas. Demonstrated ability to take open-ended research problems from 0→1 and deliver high-impact outcomes. Strong experimental skills, including experiment design, analysis, and interpretation of results. Experience writing clean, reproducible research code in Python and modern machine learning frameworks. Ability to execute quickly and independently with minimal guidance while maintaining a high bar for research quality. Experience collaborating cross-functionally with research, engineering, and product teams. Clear written and verbal communication skills, including the ability to explain complex technical ideas succinctly. Strong integrity, good judgment, and respect for others. To support close collaboration, this role is based in our San Francisco headquarters and requires in-office attendance five days a week. The expected base salary range for this role is $175,000 - $300,000 USD . In addition to base salary, we offer equity and benefits. Actual compensation will be determined based on experience, qualifications, skills, and location. Benefits Competitive salary and equity packages 15 days of paid vacation per annum Parental & sick leave Health, dental, and vision insurance plans 401(k) plan + matching In-office lunch & dinner Whoop band Monthly meal stipend Monthly health and wellness stipend Equinox membership Fun global offsites! Patronus AI is an equal opportunity employer. We celebrate diversity in our workplace, and all qualified applicants will receive consideration for employment without regard to age, ancestry, color, family or medical care leave, gender identity or expression, genetic information, marital status, medical condition, national origin, physical or mental disability, political affiliation, protected veteran status, race, religion, sex (including pregnancy), sexual orientation, or other legally protected characteristics. By clicking ‘Apply’, you agree to both of the following: 1) Greenhouse's Terms of Service and Privacy Policy 2) Patronus AI, Inc. Privacy Policy .

Requirements

Must-haves

Own ambitious research projects end-to-end , from identifying and formulating open-ended problems through experiment design, execution, analysis, and production impact.
Advance research in agent simulation, reinforcement learning, and scalable oversight , including agent cognition, behavior analysis, reward design, and new training methods.
Design state-of-the-art simulation and RL environments for training and evaluating frontier agents, spanning tools and actions, observations and state, trajectories, curricula, and reward systems.
Develop methods to understand and improve agent behavior across complex, long-horizon tasks, including reasoning, planning, adaptation, generalization, and reward hacking.
Run rigorous experiments and turn findings into measurable outcomes , including new techniques, benchmarks, datasets, environments, platform capabilities, and research publications.
Build high-quality, reproducible research systems , writing production-level code and partnering closely with engineering and product to translate research into real-world systems.
Contribute to Patronus AI’s research direction and thought leadership , staying at the frontier of the field, collaborating with the research community, and publishing or open sourcing our work.
"The number one qualification to succeed in this machine learning course is gumption” - John Lafferty, CS Professor at Yale
Above all, we look for an eagerness to learn, passion for research, creativity in problem solving and a proactive mindset. You are a great fit if you have a background in the following:
An MS or PhD in Computer Science, Machine Learning, Statistics, Mathematics, or a related quantitative field.
Experience conducting independent research in reinforcement learning, NLP, agentic systems, evaluation, alignment, or related areas.
Demonstrated ability to take open-ended research problems from 0→1 and deliver high-impact outcomes.
Strong experimental skills, including experiment design, analysis, and interpretation of results.
Experience writing clean, reproducible research code in Python and modern machine learning frameworks.
Ability to execute quickly and independently with minimal guidance while maintaining a high bar for research quality.
Experience collaborating cross-functionally with research, engineering, and product teams.
Clear written and verbal communication skills, including the ability to explain complex technical ideas succinctly.
Strong integrity, good judgment, and respect for others.
To support close collaboration, this role is based in our San Francisco headquarters and requires in-office attendance five days a week.

Nice-to-haves

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Keywords to mirror

aimachine learningpython

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Benefits

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Dental

Vision

401(K)

Wellness