Research Engineer, Reinforcement Learning

Research Engineer – Reinforcement Learning Location: San Francisco (Hybrid) About TensorStax TensorStax is building fully autonomous AI systems to manage and maintain mission-critical data infrastructure and pipelines. We leverage reinforcement learning to enhance language models' ability to reason over large-scale data lakes and warehouses, detect pipeline failures, construct new pipelines with high precision, and enable agentic behavior—allowing systems to proactively identify and resolve issues autonomously. As a Research Engineer specializing in Reinforcement Learning, you will: Develop and refine reward functions to optimize agent behavior for complex data engineering tasks. Create RL gym environments for language model agents. Fine-tune language models using reinforcement learning techniques such as PPO, DPO, and KTO. Stay at the forefront of research on RL for language models, incorporating advancements like GRPO, SWE-Gym, and SWE-RL into practical applications. Curate and build high-quality datasets for supervised fine-tuning (SFT) and RLHF. Design experiments to evaluate and improve the agentic capabilities of language models in data environments. What We’re Looking For: Deep understanding of reinforcement learning, reward shaping, and optimization strategies. Strong familiarity with LLM fine-tuning techniques (PPO, DPO, KTO) and their applications in reinforcement learning. Knowledge of recent advancements in RL for language models (GRPO, SWE-Gym, SWE-RL). Experience curating and constructing high-quality datasets for fine-tuning. Strong problem-solving skills and a history of working on complex ML projects. High agency—ability to work independently, experiment proactively, and drive research initiatives forward. Bonus Points: Experience with distributed training in PyTorch (DDP, FSDP). Hands-on experience designing RL environments for traditional RL problems. Contributions to open-source projects in RL, LLMs, or ML infrastructure. Familiarity with data lakes and warehouses (Snowflake, BigQuery, Redshift). Benefits: 100% employer-covered health, dental, and vision insurance. 401(k) with company match. Access to Bay Club or Equinox in San Francisco.