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 an Applied 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 society’s most impactful research questions surrounding agent simulations, and translate them into rigorous experiments. You will have the opportunity to work on reward design, tool simulations and behavior analysis, shaping the industry standard for robust, high quality environments. Your work will inform how frontier labs design, train and improve the next generation of agents for long-horizon tasks, progressing our path towards safe, human-aligned general intelligence.

In this role, you will:

• Solve open-ended problems in scalable oversight, including agent cognition research, agent behavior analysis and new training methods for efficient RL
• Drive novel research in RL and environment design, including reward design, trajectory evaluation, interruption handling, observation and state design, tool and action interface design, and curriculum learning
• Design and validate reward shaping strategies through reward hacking experiments to prevent exploits and ensure robust agent behavior
• Evaluate and improve agent reasoning in complex, long-horizon workflows
• Collaborate closely with engineering to productionize research, translating ideas into real-world, high-impact systems
• Build world models and state-of-the-art simulation and RL environments to train and evaluate frontier agents
• Advance agent cognition research across planning, adaptation, and generalization
• Publish papers, organize workshops and open source environments, datasets in collaboration with the evaluation research community
• Experiment with new models, techniques, and tooling, proactively proposing and running experiments to improve our understanding of agent behaviors, learning signal quality, and RL scaling
• Produce high-quality, reproducible, production-level research code that integrates cleanly into Patronus AI’s systems
• Evangelize agent simulation and environment research internally and externally, contributing to Patronus AI’s thought leadership in scalable oversight

Qualifications

"The number one qualification to succeed in this machine learning course is gumption” - John Lafferty, CS Professor at Yale

Above all, we value intellectual curiosity, strong research instincts, and the ability to turn ambiguous ideas into concrete results. You are a strong fit if you have:

• A BS, 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, or alignment.
• 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 ML frameworks.
• Ability to execute quickly with minimal guidance while maintaining high research quality.
• Experience collaborating cross-functionally with research, engineering, and product teams.
• Clear written and verbal communication skills, including the ability to explain complex ideas succinctly.
• Strong integrity, good judgment, and respect for others.

Benefits

• Competitive salary and equity packages
• Health, dental, and vision insurance plans
• 401(k) plan + matching
• In-office daily lunches and dinner
• Sponsored personal tax accounting 
• Whoop band, Oura ring, Function Health
• 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.