https://youtu.be/bq7rSJuaz7U

1. Feature order flight
2. Feature order hotel
3. Feature order train
4. Feature transaction history
5. Feature setting

1. Implement abstraction between app module and feature module using launcher module. This is to make our app module not tightly coupled to feature module.
2. Implement dynamic code loading using code generator x reflection. This is the main part how to make our module can be composable.
3. How to integrate new feature. Use case, adding order bus feature.
   • Add order bus feature module.
   • Register order bus module as feature.

Scaling an Android App from 1 to 100 developers with modularization at Airbnb. https://youtube.com/watch?v=jrnhIgFzgns&t=466s