How does .NET Core support Dependency Injection out of the box?

Short answer: .NET Core has a built-in DI container that's tightly integrated into the framework. When you create a new ASP.NET Core project, DI is configured automatically and used in controllers, middleware, services, etc. You register dependencies in the Program.cs or Startup.cs file using IServiceCollection.

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.