Principal / Sr. Principal ML Scientist (Causal Inference, Reinforcement Learning, Ranking & Bid Optimization)

Role Overview

We are looking for a Principal / Sr. Principal Applied ML Scientist to lead the development of next-generation machine learning systems powering recommendations, search, ads ranking, and monetization platforms at scale. This is a high-impact Individual Contributor (IC) role requiring deep expertise in causal inference, unbiased learning systems, reinforcement learning, and large-scale optimization techniques that improve long-term user engagement, relevance, and business outcomes.

The ideal candidate will combine strong hands-on technical depth with cross-functional influence, driving architecture, research direction, and ML best practices across Ads, Recommendations & Personalization, and Search pods.

Key Responsibilities

• Lead the design and d...