We are looking for a Staff Data Scientist to help set the strategic direction for XP, elevate the rigor of causal inference across the company, and lead the consolidation of a decade of organically-grown, bespoke experimentation practices into a unified, modern platform - all with close cross-functional collaboration with our Data Science and Engineering partners. Deep, practical knowledge of experimentation pitfalls and how to guard against them at a program level: sample ratio mismatches, winner's curse and regression to the mean, false discovery rate across a portfolio of tests, peeking, covariate adjustment, and allocation-vs-analysis-unit mismatches.