Lead RL Post-Training Scientist for Safe Healthcare AI

About Us Hippocratic AI is the leading generative AI company in healthcare. We have the only system that can have safe, autonomous, clinical conversations with patients. We have trained our own LLMs as part of our Polaris constellation, resulting in a system with over 99.9% accuracy. Why Join Our Team Reinvent healthcare with AI that puts safety first. We’re building the world’s first healthcare‑only, safety‑focused LLM — a breakthrough platform designed to transform patient outcomes at a global scale. This is category creation. Work with the people shaping the future. Hippocratic AI was co‑founded by CEO Munjal Shah and a team of physicians, hospital leaders, AI pioneers, and researchers from institutions like El Camino Health, Johns Hopkins, Washington University in St. Louis, Stanford, Google, Meta, Microsoft, and NVIDIA. Backed by the world’s leading healthcare and AI investors. We recently raised a $126M Series C at a $3.5B valuation, led by Avenir Growth, bringing total funding to $404M with participation from CapitalG, General Catalyst, a16z, Kleiner Perkins, Premji Invest, UHS, Cincinnati Children’s, WellSpan Health, John Doerr, Rick Klausner, and others. Build alongside the best in healthcare and AI. Join experts who’ve spent their careers improving care, advancing science, and building world‑changing technologies — ensuring our platform is powerful, trusted, and truly transformative. Location Requirement We believe the best ideas happen together. To support fast collaboration and a strong team culture, this role is expected to be in our Palo Alto office five days a week, unless otherwise specified. About the Role LLM post-training is where raw capability becomes reliable, safe behavior — and in healthcare, the stakes are as high as they get. You'll own the RL-based post-training pipeline end-to-end to improve our models' clinical reasoning, safety, and alignment. Your models will be deployed to interact with millions of patients across diverse clinical use cases. What You’ll Do Design and iterate on RL-based post-training methods (RLHF, RLVR, DPO, and beyond) Build and evaluate reward models, verifiers, and LLM-as-judge pipelines Develop conversational AI environments and simulations for healthcare RL training with synthetic data Run rigorous experiments to understand what drives post-training gains Collaborate with research, engineering, and clinical teams What You Bring Must-Have: MS or PhD in CS or relevant field 4+ years or experience in NLP, LLM training, RL, or general ML 1+ years experience in RL for LLM post-training Experience with large-scale (50B+ parameter and multi-node) LLM training Strong Python and PyTorch coding skills Experience with RLHF, RLVR, LLM-as-judge or similar methods for LLM post-training Nice-to-Have: Publications at top venues (NeurIPS, ICML, ICLR, ACL, EMNLP) Healthcare domain experience References 1. Polaris: A Safety-focused LLM Constellation Architecture for Healthcare, 2 . Polaris 2: 3 . Personalized Interactions: 4 . Human Touch in AI: 5 . Empathetic Intelligence: 6 . Polaris 1: 7 . Research and clinical blogs: Please be aware of recruitment scams impersonating Hippocratic AI. All recruiting communication will come from @ hippocraticai.com email addresses. We will never request payment or sensitive personal information during the hiring process. #J-18808-Ljbffr Hippocratic-Ai