← All roles

Research Engineer - Environments, Data and Post-Training

Mercor· Research
Apply on company site
San Francisco$180k - $500kFull-timePosted 9mo ago

About the role

Research Engineer focusing on post-training and RLVR, synthetic data generation, and large-scale evaluation workflows to improve frontier language models. Combines engineering with applied AI research in a fast-paced, high-ownership environment.

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.
  • Operate in a fast-paced, experimental research environment with rapid iteration cycles and high ownership.

Qualifications

  • 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.
  • Excitement to work in person in San Francisco, five days a week (with optional remote Saturdays), and thrive in a high-intensity, high-ownership environment.

Skills

Required:Post-training and RLVR researchProgramming and ML model workData systems and backend fundamentals

Benefits

  • Bi-annual performance bonus structure
  • Generous equity grant vested over 4 years
  • Up to $15k Relocation bonus
  • $10K housing bonus (if you live within 0.5 miles of our office)
  • $1.5K monthly stipend for meals
  • Free Equinox membership
  • $200 monthly laundry reimbursement
  • $200 monthly personal wellness reimbursement
  • Health, Dental, Vision insurance
Last updated Sep 9, 2026. Interested? Apply on the company site.

About Mercor

Shape the future of work

Find top-tier, remote, AI roles for your expertise. Available only on Mercor.

AIremotejobstechnology
Company profileWebsite

More open roles at Mercor