Microsoft.FeatureManagement Library Makes .NET Feature Flags Simple and Scalable

Microsoft's FeatureManagement library for .NET integrates natively with the framework's configuration and dependency injection systems, allowing developers to implement feature flags with minimal setup. Flags are defined as boolean values in appsettings.json and accessed via the IFeatureManager interface, which can be injected into any controller or service. Beyond simple on/off toggles, the library supports advanced feature filters such as percentage-based rollouts, time windows, and user targeting. Razor tag helpers are also included, enabling conditional rendering of UI elements without embedding C# logic in markup. However, the appsettings.json approach still requires a config change and redeployment to toggle flags, a limitation that dedicated feature flag management tools are designed to address.