Develop and execute functional, integration, regression, and user-acceptance test cases; validate and reconcile data exchanged through APIs and other integration processes; capture scripts, datasets, screenshots, logs, and results for auditability; and support preparation of API and Data Quality Validation Reports. Collaborate with data owners, stewards, engineers, administrators, and mission users to profile prioritized datasets; establish business definitions, domains, classifications, quality rules, baselines, and thresholds; and connect business terminology with technical data assets.