Modularization and App Size

As an app grows, more teams and features share the same codebase. Modularization helps define which code belongs together and how one part may use another.

A module is a code or build boundary with a defined public interface. It is not automatically a screen, a layer, or a separately downloadable feature.

Start with responsibilities and dependencies

Consider a shopping app with Product and Cart features. Product needs to add an item to the cart, but it should not need to understand Cart's database tables or screen implementation.

One possible structure is: