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Research Engineer - Environments, Data and Post-Training

San Francisco💼 Full-time🗓 2026-09-18 → 2026-09-25

Core

Develop novel post-training methods, training recipes, and evaluation systems to improve frontier AI model reasoning, tool use, and agentic behavior.

Role type

Senior IC research engineer (post-training & RL)

Builds

Scalable post-training pipelines, RLVR systems, data generation/filtering infrastructure, and evaluation benchmarks

Domain

Artificial Intelligence, Reinforcement Learning, Frontier Model Optimization

Deliverable

production ML models

Required skills

Post-training methods, Reinforcement Learning, Language-model evaluation, Data-centric ML, Experimental design, Python programming, Distributed systems

Preferred skills

Synthetic-data generation, Large-scale evaluation infrastructure, Cloud infrastructure, Open-source contributions

Responsibilities

Implement novel post-training methods for model reasoning and tool use, Design and run experiments on datasets and reward functions, Build RLVR and post-training pipelines at scale, Develop rubrics, evaluators, and benchmarks for training decisions, Create methods for measuring data quality and causal impact, Translate research questions into rigorous experiments and production systems

Seniority

Senior, hands-on IC

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