What are Feature Flags?

Introduction to Feature Flags

Feature flags (also known as feature toggles or feature switches) are a powerful technique that allows teams to modify system behavior without changing code. They provide a way to control the visibility and behavior of features in your application.

What are Feature Flags?

Feature flags are conditional statements in your code that determine whether a particular feature is enabled or disabled. They allow you to:

Gradually roll out new features to users
Test features in production without affecting all users
Quickly disable problematic features
Enable features for specific user segments
Perform A/B testing and experimentation

Benefits of Feature Flags

Continuous Delivery

Ship code to production without exposing features to users until they're ready.

Risk Management

Quickly disable features that cause issues without deploying new code.

User Testing

Test features with specific user segments before full rollout.

Experimentation

Run A/B tests and gather data to make informed decisions.

Types of Feature Flags

Release Flags

Control the visibility of new features during development and release.

Operational Flags

Manage system behavior and performance in production.

Permission Flags

Control access to features based on user roles and permissions.

Experiment Flags

Enable A/B testing and user behavior experiments.

Example Usage

Here's a simple example of how feature flags work in code:

// Check if a feature is enabled
if (isFeatureEnabled('new-dashboard')) {
  // Show new dashboard
  renderNewDashboard();
} else {
  // Show old dashboard
  renderOldDashboard();
}

This allows you to control which dashboard users see without changing the code.