We build and operate large-scale data infrastructure and data assets - ingesting, validating, harmonizing, and vending data from 20+ third-party providers (agencies, aggregators, publishers) across multiple Amazon business units and marketing channels, with global coverage. As an SDE II, you"ll design and build the systems that transform and harmonize data from 20+ external partners - each with their own schemas, grains, cadences, and nuances - into the measurement-grade inputs that power COSMOS, Amazon"s FM causal measurement framework.