Dependency Injection in .NET and ASP.NET Core with Interview Prep

Writing tightly coupled C# code makes applications fragile, difficult to test, and hard to maintain over time. Learning how to properly decouple your classes using dependency injection is one of the most impactful steps you can take to elevate your software development career. This text-based course guides you from the fundamental concepts of dependency injection (DI) to advanced architectural patterns in .NET and ASP.NET Core. You will learn how to design flexible, testable systems, manage service lifetimes correctly, and confidently answer DI-related architectural questions in your next technical interview. What you'll learn: - Understand the core principles of inversion of control, dependency injection, and loose coupling. - Configure transient, scoped, and singleton service lifetimes to avoid memory leaks and captive dependencies. - Apply modern C# features like primary constructors and keyed services for clean dependency registration. - Implement dependency injection in ASP.NET Core controllers, minimal APIs, and custom middleware. - Practice writing unit tests by mocking dependencies to isolate and verify your business logic. - Prepare for technical job interviews with targeted questions and detailed explanations of real-world design patterns. You will start with core architectural definitions before moving on to hands-on configuration examples, service lifetimes, and advanced registration strategies. The course concludes with a dedicated focus on testing patterns and standard interview scenarios. This course is designed for beginner to intermediate C# developers looking to transition from basic programming to professional application architecture. No prior experience with dependency injection frameworks is required. Read through the concepts, review the code implementations, and start writing cleaner C# code today.