What approaches and methods should be used to manage variability in a project?

Several approaches are used to manage variability in an Android project:

• Using build flavors and build types in Gradle. Allows creating different versions of the app with varying functionality, resources, and configurations.

• Implementing design patterns such as Strategy or Factory. Enables changing component behavior without modifying their code.

• Using Dependency Injection (e.g., Dagger or Hilt). Allows replacing dependency implementations depending on the build variant or environment.

• Configuration files and resources. Different resources (strings, images, styles) for different app variants.

• Feature toggles. Allow enabling or disabling functionality dynamically.

Example of using build flavors in Gradle:

android {
    flavorDimensions "version"
    productFlavors {
        free {
            dimension "version"
            applicationIdSuffix ".free"
            versionNameSuffix "-free"
        }
        paid {
            dimension "version"
            applicationIdSuffix ".paid"
            versionNameSuffix "-paid"
        }
    }
}

This approach allows maintaining multiple app variants with different functionalities and configurations within a single project.