Real Subject (RealImage):?

Short answer: The RealImage class implements the IImage interface and represents the actual object that we want to control access to.

Explain a bit more

It contains the logic to load and display the image. public class RealImage : IImage public void Display() => Console.WriteLine($"Displaying {_filename}"); } Behavior: The RealImage object is only loaded once the Display() method is called. This behavior can be resource-intensive, especially if the image is large.

Example code

{
private readonly string _filename;
public RealImage(string filename) => _filename = filename;

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.