You have multiple services that need to access a common configuration. The configuration should be centralized, and changes should be propagated in real-time. What GCP service would you use?

The Cloud Runtime Configuration API is designed for storing and managing dynamic configuration data for applications. It allows services to retrieve configurations and receive real-time updates when changes occur, making it ideal for centralized configuration management with propagation. Cloud Storage is suitable for static files but doesn't offer real-time change propagation for configuration. Cloud Pub/Sub is a messaging service, not a configuration store. Cloud SQL is a relational database, overkill for simple configuration and not optimized for real-time updates to many services. Firestore is a NoSQL document database that could store configuration, but Runtime Config API is purpose-built for this use case with real-time updates. Cloud Memorystore is an in-memory data store, good for caching, but not the primary solution for persistent, centrally managed configuration with real-time updates.