How do you handle cross-cutting concerns (like logging) in a SOLID way?

Short answer: Use AOP (Aspect-Oriented Programming) techniques or design patterns like Decorator to separate cross-cutting concerns from business logic. In .NET, middleware, filters, or interceptors can manage concerns like logging or authorization, keeping SRP intact.

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.