Tell about your experience applying the VIPER architectural pattern in projects.

In iOS projects, I used the VIPER architectural pattern to separate responsibilities and improve code testability. VIPER divides functionality into five components:

• View — displays the interface and interacts with the user.
• Interactor — business logic and data processing.
• Presenter — intermediary between View and Interactor, formats data for display.
• Entity — data models.
• Router — navigation between screens.

This approach helps maintain a clean architecture, facilitates modular testing, and simplifies project scaling. For example, in one project, I implemented a user profile screen where the Interactor was responsible for loading data from the network, the Presenter formatted it for display, and the Router managed transitions to other screens.

VIPER requires more initial setup time but improves code quality and maintainability in the long run.