Client Code (Application):?

Short answer: The Application class accepts an IUIFactory in its constructor. This means the client code can choose which concrete factory (Windows or Mac) to use without changing the Application class itself. public class Application

Example code

{
private readonly IButton _button;
private readonly ICheckbox _checkbox;
public Application(IUIFactory factory)
{
_button = factory.CreateButton();
_checkbox = factory.CreateCheckbox();
}
public void Render()
{ _button.Render(); _checkbox.Render(); }
}

Real-world example (ShopNest)

Use a GoF pattern in ShopNest only when it removes duplication or makes a change safer—explain the problem it solves in the interview.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.