How do you implement DI in ASP.NET Core MVC?

Short answer: ASP.NET Core MVC has built-in support for Dependency Injection.

Explain a bit more

Register services in Startup.cs within ConfigureServices method using IServiceCollection: public void ConfigureServices(IServiceCollection services) { services.AddControllersWithViews(); services.AddScoped<IProductService, ProductService>(); // Example } Inject dependencies via constructor injection in controllers or services: public class HomeController : Controller

Example code

{
private readonly IProductService _productService;
public HomeController(IProductService productService)
{
_productService = productService;
}
public IActionResult Index()
{
var products = _productService.GetAll();
return View(products);
}
} The framework resolves and injects dependencies automatically.

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.