Founding Research Engineer

The LLM Data Company • San Francisco, CA

120d

About The Position

The LLM Data Company (YC X25) provides post-training data and RL environments to foundation model labs and frontier applied AI companies. We have raised $3.6m from Tier 1 VCs and are growing 200%+ month-over-month.

Requirements

• Bachelor or Master in Computer Science or related field
• Comfort with core tooling (verl, PyTorch, etc.)
• Familiarity with modern post-training techniques (GRPO, etc.)
• Experience with evaluations and reward engineering
• Published in top journals (ICLR, NeurIPS, ICML, etc.)

Responsibilities

• Design and implement scalable RL recipes for post-training task-specific models
• Develop modular environments, reward functions, and evaluator scaffolds for internal and customer-facing tasks
• Drive research at the intersection of scalable infra and modern RL frameworks to enable RL-as-a-service
• Drive foundational research to publish open source environments and training data
• Build data generation and curation pipelines to support frontier post-training
• Collaborate with product teams to deliver a user friendly interface for non-technical users to generate data

Benefits

• Cutting-edge research: Work on unpublished, novel training environments
• Direct lab exposure: Projects that labs actually use and validate in production
• High autonomy: Wide design space to propose and run experiments with minimal oversight
• Early team member: Join as one of the first 10 people with significant equity upside

What This Job Offers

• Education Level: Bachelor's degree