Member of Technical Staff - Research Engineer, RL Environments

The role

You will design and build reinforcement learning environments and reward functions for frontier models. This role involves conducting experiments, delivering work into production training runs, and collaborating with researchers and engineers.

What you will do

• Design and build RL environments and reward functions that produce clean, learnable signals for frontier models on ML research and engineering tasks
• Build deep expertise across the frontier of ML research, training, and inference infrastructure
• Collaborate with others to brainstorm and create new ideas and tools to improve the environment building process
• Stay up to date with the latest research
• Develop novel approaches and realize them in code
• Conduct experiments and evaluations
• Deliver work into production training runs

Required qualifications

• 5+ years of experience working in machine learning or research, primarily on LLMs and transformer models
• Strong ML fundamentals and broad research interests
• Proficiency in Python and systems programming
• At least one of PyTorch or JAX
• Problem solvers who take ownership and drives solutions end-to-end
• Passion for staying current with the rapidly evolving ML infrastructure landscape
• Ability to meet throughput expectations and respond quickly to feedback

Nice to have

• Expert knowledge in an active DL/ML research area, with publications or public code to show for it
• Research experience (PhD, MS)
• Deep understanding of transformer internals, training/inference of modern LLMs
• Experience with inference libraries (vLLM, SGLang, etc)
• Strong expertise in kernel development (CUDA, Triton, Pallas)
• Built complex interactive RL environments

Benefits

• Competitive cash and equity compensation (>90th percentile)
• Ownership and autonomy in a fast moving startup environment
• Opportunity to work with top machine learning engineers
• Health, vision, dental, benefits
• 401K match
• Lunch provided everyday onsite
• Weekly snack orders
• Visa sponsorship & relocation support available

Before you apply

• This role is only for experienced ML Engineers

About the company

Preference Model is a superintelligence data research company. They build RL environments for training capable, better-aligned superintelligences.