Principal Applied Scientist, Agentic AI

About the teamZillow is investing deeply in next‑generation AI and machine learning to power intelligent experiences across our products, helping customers and partners make better decisions in a complex, real‑world domain. Our team brings together Applied Scientists, ML engineers, and Software engineers who own the full lifecycle of large‑scale systems that combine modern foundation models with applied ML-from data and modeling through evaluation and deployment. We collaborate closely with platform, product, and operations partners in a fast‑moving, remote‑first environment where experimentation, learning, and shipping are core to how we work.About the roleAs a Principal Applied Scientist focused on RL post‑training, you will lead the design and deployment of learning systems that shape how our models behave in real products. You will own the technical direction and strategy for post‑training and adaptation of large models to align behavior with user value, safety, and business objectives. This is a high‑impact principal IC role with broad influence across Zillow, working closely with senior leadership to ensure our investments translate into safer, more capable, and more trusted AI‑powered experiences.You will get to:Lead the technical direction and strategy for RL post‑training of production models, partnering with other scientists, engineers, and product leaders to align models with customer and business needs.Design and implement post‑training pipelines that combine techniques such as supervised fine‑tuning on curated demonstrations, preference modeling and pairwise ranking, and RL‑based alignment approaches like RLHF, RLAIF, or DPO for multi‑objective optimization.Develop reward models and objective formulations that balance constraints such as helpfulness, safety, fairness, compliance, and customer satisfaction, and iterate on them using human and AI feedback at scale through online and batch adaptation loops with strong guardrails.Translate conversational lo