Staff Research Scientist / Reinforcement Learning

About the role

A cutting-edge AI company is hiring a Staff AI Researcher to lead a small team while remaining hands-on across reinforcement learning and LLM post-training. This is a role where researchers take ownership over their work, collaborate closely with leadership, and help shape the technical direction of the organization.

Responsibilities

• Take ownership over their work and contribute individually to cutting-edge RL research and implementation
• Mentor junior researchers
• Build and improve RLHF pipelines
• Develop reward models
• Design post-training workflows using approaches like PPO, DPO, GRPO, KTO, and similar methods
• Work closely with evaluation frameworks to identify model weaknesses
• Build reinforcement learning environments
• Translate research into production-ready improvements

Requirements

• 5+ years of experience in AI Research, Applied Research, or Machine Learning
• PhD in Computer Science, Machine Learning, or a related technical field preferred
• 3+ years of experience fine-tuning LLMs using RLHF, PPO, DPO, GRPO, or similar post-training methods
• Experience building reinforcement learning environments, evaluation frameworks, and benchmark-driven systems
• Experience with modern post-training libraries such as TRL, OpenRLHF, veRL, SkyRL, or similar
• Strong publication record at ICML, NeurIPS, ICLR, ACL, or similar conferences preferred
• Experience mentoring researchers or leading technical initiatives while remaining hands-on
• Strong Python experience implementing machine learning research into production systems

Qualifications

• Hands-on experience fine-tuning frontier models
• Publishing RL research
• Leading technical initiatives in a collaborative research environment

Skills

• Experience with reinforcement learning and LLM post-training techniques
• Ability to build and improve RLHF pipelines, reward models, and post-training workflows
• Proficiency in modern post-training libraries
• Strong publication record in relevant fields
• Experience mentoring researchers or leading technical initiatives
• Strong Python skills for implementing machine learning research

Benefits

• Equity
• Paid Time Off
• Medical, dental, and vision coverage
• Opportunity to create lasting impact within a growing organization
• Opportunity to lead and grow a high-performing research team
• Hybrid working schedule