Subsystem Classes (Amplifier, DVDPlayer): ○ These classes represent the components of the complex subsystem. They have specific functionalities but are complicated to interact with individually.

Short answer: mplifier: public class Amplifier { public void On() => Console.WriteLine("Amplifier is on."); public void Off() => Console.WriteLine("Amplifier is off."); } DVDPlayer: public class DVDPlayer { public void Play(string movie) => Console.WriteLine($"Playing {movie}."); } mplifier: public class Amplifier { public void On() => Console.WriteLine("Amplifier is… public void Off() => Console.WriteLine("Amplifier is off."); }…

Example code

{
public void Play(string movie) => Console.WriteLine($"Playing {movie}."); }

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.