Priceline.com implemented a GraphQL supergraph to unify its data and services, including sensitive PCI data, into a single graph. This allowed them to selectively expose only necessary data to different audiences, such as client apps, while keeping sensitive information private. To restrict access to sensitive data, they created contract graphs using Apollo Studio, which derived a filtered subset of the supergraph schema based on tags applied to subgraph schemas and filters defined in Apollo Studio. This approach eliminated duplicative maintenance work and provided a single source of truth for definitions of every entity in their data model. With this setup, Priceline can now power nearly all of its experiences with a single endpoint while maintaining security and scalability.