Feature Flag Management in .NET Core: A Complete Guide with Real-World Examples

1. Introduction

In modern software development, applications continuously evolve. Developers regularly introduce new features, improve existing functionality, fix bugs, and experiment with new business requirements.

Traditionally, whenever a new feature was developed, developers had to deploy the application to make that feature available to users.

But what if we want to:

Release a feature without making it available to everyone?

Enable a feature only for selected users?

Release a feature to 10% of users and gradually increase it to 100%?

Disable a problematic feature without redeploying the application?

Enable a feature only during a particular time period?

Test a new implementation without affecting existing customers?

This is where Feature Flag Management comes into the picture.

Feature flags (also known as feature toggles) allow developers to control application functionality dynamically without changing or…