Replacing Switch Statements with the Factory Pattern in C#

My annual spring sale is now live. Check it out: https://www.milanjovanovic.tech/sprin... Get the source code for this video here → https://the-dotnet-weekly.kit.com/fac... Want to master Clean Architecture? Go here: https://dub.sh/clean-architecture Want to master Modular Monoliths? Go here: https://dub.sh/modular-monolith Join the .NET Architects Club: https://www.skool.com/mj-tech-communi... Get the 2026 .NET Developer roadmap here → https://the-dotnet-weekly.ck.page/202... What happens when one service becomes responsible for creating dependencies, reading configuration, selecting implementations, and executing business logic? You end up with code that is harder to test, harder to extend, and harder to maintain. In this tutorial, I’ll refactor a messy NotificationService that supports email, SMS, and Slack notifications using the Factory Pattern in .NET. We’ll clean up the initial implementation, extract notification senders behind an interface, introduce a factory abstraction, and wire everything together with dependency injection. You’ll learn how to: Recognize when object creation is making your service too complex Remove duplicated logic and replace magic strings with enums Encapsulate notification implementations behind INotificationSender Implement a factory using a dictionary-based approach Use .NET keyed services for cleaner dependency resolution Extend the system with a new notification channel Understand the difference between the Factory and Strategy patterns By the end, our original service becomes much smaller, easier to test, and easier to extend without adding more conditional logic. Check out my courses: https://www.milanjovanovic.tech/courses Read my Blog here: https://www.milanjovanovic.tech/blog Join my weekly .NET newsletter: https://www.milanjovanovic.tech Chapters