Hiring: Research Engineer, LangSmith Engine Company: LangChain Location: New York, NY Job Posted Time: 2026-09-10 13:40:13 Target Skills & Keywords : Cloudflare, Fine-tuning, LLM, LangChain, Machine Learning, Monday.com, Reinforcement Learning, Workday About the job Experience: •4+ years of experience in ML/AI research, or a closely related field. Required Skills: •We’re looking for an experienced research engineer to help make the Engine agent more capable and more efficient. •You’ll study real agent failures, build benchmarks that capture what matters, run experiments to improve performance, and turn successful ideas into production. This may include prompting and agent-harness improvements, model selection, fine-tuning and post-training custom models. •The focus is on measurable improvements to the overall agent. •This role also requires a understanding of production engineering and system-level tradeoffs •. Engine is a production system, so improving an agent is not just about maximizing benchmark performance—it also means understanding the impact on cost, latency, reliability, and scalability •. You’ll work in the same team with production engineers to design, test, and ship improvements that work reliably in real-world environments. •Build and maintain benchmarks and evaluations that measure the quality and efficiency of Engine agents on real-world tasks. •Design and run experiments to improve agent performance across models, prompting, context, tools, orchestration, and agent strategies. Qualifications: •Ph.D. in Machine Learning, Computer Science or Physics. •Applied hands-on capability in LLM-as-a-judge, automated graders, synthetic data generation, or human evaluation. •Applied hands-on capability in reinforcement learning, preference optimization, SFT, RLHF/RLAIF, or other post-training techniques for LLMs. Compensation: •Competitive benefits and rewards package •We offer competitive compensation that includes base salary, variable compensation for relevant roles, meaningful equity, benefits, and perks Interested candidates, please apply directly through the job posting on company's career page or try via AI auto apply on this platform. Don't miss this opportunity to join a forward-thinking team!