Notification Flow:?

Short answer: When the publisher publishes new news via the Notify() method, each observer’s Update() method is called, and the news is sent to all registered subscribers. Benefits of the Observer Pattern:

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.