Use the Azure App Configuration provider ' s caching and dynamic refresh mechanism with a configured refresh interval . The application loads configuration into a local cache and periodically checks App Configuration for changes. When a registered key changes, the provider refreshes the cached configuration without requiring an application restart. Microsoft documents SetRefreshInterval and equivalent provider settings as the mechanism for controlling the minimum time between configuration-refresh checks.
This approach satisfies both requirements. The configuration is dynamic because updated values can be detected and reloaded at runtime, while request latency remains low because normal application requests read configuration from the local cached copy instead of making a remote App Configuration request every time.
For request-driven refresh, Microsoft notes that refresh occurs asynchronously and does not block the incoming request. Before the configured refresh interval expires, additional refresh calls effectively perform no remote operation.
Microsoft also recommends caching App Configuration values instead of loading them whenever they are used, both to reduce latency and to avoid excessive service requests, throttling, and unnecessary charges.
Environment variables remain static unless the application is restarted or redeployed. Retrieving configuration on every request increases latency and service load. Key Vault is primarily intended for secrets, not general dynamic application configuration.
Study Guide references: Azure App Configuration; dynamic configuration refresh; provider caching; refresh intervals; request-driven refresh; configuration resiliency.