Policy Zones: How Meta enforces purpose limitation at scale in batch processing systems

Meta’s Privacy Aware Infrastructure (PAI) slams Governable Data Annotations (GDAs) at runtime. It parses SQL across its exabyte-scale warehouse and blocks any flow that flouts purpose-use policies. It welds Unified Programming Model (UPM), Policy Evaluation Service (PES), Warehouse Permission Service (WPS), PrivacyLib, Policy Zones Manager (PZM) and Dr Policy Zone (Dr. PZ) into one relentless consent engine. They vet trillions of checks.