Refactoring a 500-Line Method with the Pipeline Pattern

Milan Jovanović demonstrates how to refactor a complex, nested method in .NET into a clean, maintainable pipeline that adheres to the Open-Closed Principle.

Want to master Clean Architecture? Go here: dub.sh/clean-architecture Want to master Modular Monoliths? Go here: dub.sh/modular-monolith Join the .NET Architects Club: skool.com/mj-tech-community-5418/about Get the 2026 .NET Developer roadmap here → the-dotnet-weekly.ck.page/2026-roadmap Ever opened a class to add one simple business rule, only to find a 500-line monster of chained if-else statements? We’ve all been there. It makes testing a nightmare and introduces the constant fear of breaking existing logic. In this video, I'll show you a better way to handle this using the Pipeline Pattern in .NET. We’ll take a messy, typical enterprise-level Loan Eligibility Service and refactor it step-by-step into a clean, flexible pipeline that respects the Open-Closed Principle. What we cover in this video: - Extracting complex logic into isolated classes using an IEligibilityRule interface. - Creating an EligibilityContext to track application state, warnings, and rejections. - Building and executing the EligibilityPipeline. - Wiring everything up seamlessly using Dependency Injection in .NET. - A quick comparison between the Pipeline, Strategy, and Chain of Responsibility patterns. If you found this helpful, consider gently tapping the like button! Let me know in the comments how you currently handle massive validation classes in your own projects. Check out my courses: milanjovanovic.tech/courses Read my Blog here: milanjovanovic.tech/blog Join my weekly .NET newsletter: milanjovanovic.tech Chapters