Data Quality and Validation

A deployment lives or dies on the customer's data, and that data is worse than their sample suggested. The job is to build automated quality gates (schema, null, range, uniqueness, freshness) at the boundary, quarantine bad records instead of failing the whole batch, and alert on the rate so a Tuesday-shaped degradation surfaces before a dashboard goes wrong. This is the difference between a pipeline that fails loudly and one that lies quietly.