Research Engineer

Responsibilities

• Work on post-training and RLVR pipelines to understand how datasets, rewards, and training strategies impact model performance
• Design and run reward-shaping experiments and algorithmic improvements (e.g., GRPO, DAPO) to improve LLM tool-use, agentic behavior, and real-world reasoning
• Quantify data usability, quality, and performance uplift on key benchmarks
• Build and maintain data generation and augmentation pipelines that scale with training needs
• Create and refine rubrics, evaluators, and scoring frameworks that guide training and evaluation decisions
• Build and operate LLM evaluation systems, benchmarks, and metrics at scale
• Collaborate closely with AI researchers, applied AI teams, and experts producing training data

Requirements

• Strong applied research background with a focus on post-training and/or model evaluation
• Strong coding proficiency and hands-on experience working with machine learning models
• Strong understanding of data structures, algorithms, backend systems, and core engineering fundamentals
• Familiarity with APIs, SQL/NoSQL databases, and cloud platforms
• Ability to reason deeply about model behavior, experimental results, and data quality
• Ability to work in person in San Francisco five days a week

Preferred Qualifications

• Real-world post-training team experience in industry
• Publications at top-tier conferences (NeurIPS, ICML, ACL)
• Experience training models or evaluating model performance
• Experience in synthetic data generation, LLM evaluations, or RL-style workflows
• Work samples, artifacts, or code repositories demonstrating relevant skills

Benefits

• Bi-annual performance bonus structure
• Generous equity grant vested over 4 years
• Up to $15k Relocation bonus
• $10K housing bonus for living within 0.5 miles of the office
• $1.5K monthly stipend for meals
• Free Equinox membership
• $200 monthly laundry reimbursement
• $200 monthly personal wellness reimbursement
• Health, Dental, and Vision insurance

About the Company

Mercor's mission is to organize human intelligence to power the AI economy. We partner with leading AI labs and enterprises to provide the human intelligence essential to AI development.