CodeOpinion: You Don’t Need an Interface for Everything

You Don’t Need an Interface for Everything

You’ve probably seen the parade of IOrderService, IEmailService, IPaymentService in every .NET project—each with a single implementation. This video argues most of those interfaces are dead weight, born from how Dependency Injection is taught. Instead, it digs into when interfaces truly matter (think plug-and-play swaps, mocking, or extending behavior) and when they just clutter your code.

As an alternative, you’ll see how simple delegates or overrides can give you the same flexibility without the extra abstraction. By tracing the roots of this habit in DI tutorials, the talk offers a leaner, more pragmatic approach to designing services.

Watch on YouTube