How do SOLID principles help in microservices architecture?

Short answer: SOLID promotes small, single-responsibility services (SRP), clear interfaces (ISP), loose coupling (DIP), and extendable design (OCP). This aligns well with microservices by encouraging modular, maintainable, and testable service boundaries.

Real-world example (ShopNest)

Open/Closed in ShopNest: add a new payment method by adding a class, not by editing a giant switch in CheckoutService.

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.