As a Principal Data Scientist, you’ll be a technical leader responsible for the full lifecycle of the models and data science systems that predict and optimize advertising performance across channels. You’ll define the learning problems, training data, targets, and business outcomes to influence; train and rigorously validate the right models offline; and take the technology to market through customer-facing validation. You’ll work across paid social, search, display, video, and emerging channels, translating complex, noisy advertising data into robust models, explainable decisions, and measurable customer value as our platform and data scale.