Concrete Component (SimpleCoffee):?

Short answer: The SimpleCoffee class is the basic concrete implementation of the ICoffee interface. It represents a basic coffee order with a cost and description. public class SimpleCoffee : ICoffee

Example code

{
public double Cost() => 1.00;
public string Description() => "Simple Coffee";
}

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.