How does the SOLID principle relate to OOP?

Short answer: SOLID principles are design guidelines that enhance maintainability, flexibility, and scalability of OOP systems. They guide proper use of abstraction, inheritance, encapsulation, and polymorphism.

Real-world example (ShopNest)

ShopNest splits “save order” and “send email” into different services (SRP). The order service depends on IEmailSender (DIP), so unit tests can fake email.

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.