SOLID w C# — zły kod vs dobry kod na przykładach

Download the FREE Junior .NET Developer roadmap + 7 days of access: https://dev-hobby.pl/ Code for this episode on Github: https://github.com/mariuszjurczenko/D... SOLID in C# explained on a REAL project, each in the following pattern: bad code → good code → rule → live test. At the end, 36 green tests, zero infrastructure (0 databases, 0 SMTP, 0 networks). This is level 3 of the Junior .NET roadmap—the very principles of SOLID in C# that recruiters ask about during job interviews. 🎯 What you'll learn: • Single Responsibility — One Reason to Change (OrderService Refactoring) • Open/Closed — Extending Without Modification (Strategy in a Payment System) • Liskov Substitution — Safe Subtyping • Interface Segregation — Small Interfaces Instead of a "Fat" IService • Dependency Inversion — Dependency on Abstractions (DIP vs. Dependency Injection) ⏱️ Chapters: 00:00 Introduction — Why SOLID Changes the Way You Think About Code 00:29 S — Single Responsibility (OrderService, e-commerce) 03:54 O — Open/Closed (Payment System) 07:38 L — Liskov Substitution (Rectangle/Square + Bird/Ostrich) 12:10 I — Interface Segregation (Reporting System) 15:22 D — Dependency Inversion (Notification System) 19:00 Live Testing — 36 Tests, Zero Infrastructure 20:38 Summary + Junior .NET Roadmap If you're learning C# and .NET, these SOLID principles are the foundation of clean code, design patterns, and Clean Architecture. Save the video, revisit the examples, and practice with your own code. ________________________________________ ✋ Join the Dev-Hobby community: Blog with tech-heavy content: https://dev-hobby.pl/solid/zasady-sol... 💬 Leave a comment: which of the 5 SOLID principles was the most challenging for you? I read and respond to every comment. 👉 Subscribe to @mariuszjurczenko — weekly C#/.NET specifics for beginners. #csharp #dotnet #solid