How do you avoid God classes in .NET applications?

Short answer: Apply Single Responsibility Principle (SRP) by splitting responsibilities into smaller classes. Use composition instead of inheritance to delegate behavior. Extract business logic into services or helpers. Introduce abstractions to isolate concerns. Continuously refactor large classes and add unit tests.

Real-world example (ShopNest)

Patterns in ShopNest should solve a real pain (swappable payments, test seams)—not be added for decoration.

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.