C-Sharp

This guide covers 22 clean code principles in C# that go beyond SOLID, naming, error handling, layering, and API design for real-world maintainable systems.

Real benchmark results comparing IAsyncEnumerable and Task.WhenAll. Learn when to choose speed vs responsiveness, memory efficiency, and user experience in C# async operations.

Copy-paste coding may seem convenient, but it often causes hidden bugs. Learn practical C# patterns to replace duplication and maintain clean, maintainable code.

TL;DR In multi-tenant SaaS, generic audit logging can easily leak data between tenants. This is a security and compliance nightmare. Overriding DbContext.SaveChanges() is a common but clunky solution that tightly couples auditing logic to your data context. EF Core Interceptors provide a clean, decoupled way to hook into the save process and add per-tenant audit logs automatically. The solution involves creating a SaveChangesInterceptor, grabbing the current TenantId from a scoped service, and logging entity changes before they hit the database. This pattern is perfect for auditable, compliant SaaS applications but might be overkill for simple, single-server projects. I once got a panicked call about a critical bug. An admin from “Company A” could see user creation events from “Company B” in their audit trail. It was a classic multi-tenant data bleed, but not in the main application data—it was in the logs. This is one of those sneaky bugs that passes all unit tests but can absolutely destroy trust with your customers and fail a compliance audit. ...

Most projects I review have a Utils or Helpers class packed with static methods. At first glance, static helpers look like the fastest way to solve problems. You don’t need to new up objects or wire dependencies. Just call Helper.DoSomething() and move on. That convenience is exactly why they sneak into codebases. But over time, static helpers turn into a source of pain, especially in production systems that need to evolve. ...

Learn how to avoid common ASP.NET Core dependency injection lifetime mistakes. This guide covers DbContext misuse, scope leaks in singletons, transient performance traps, background service issues, and middleware lifetime bugs with real production fixes.

Master SOLID principles with real C# examples, interview questions, common pitfalls, and clean architecture tips for maintainable, testable code.

Want the PDF version? Click here to download S: Single Responsibility Principle (SRP) Real Meaning: One reason to change, not one “thing” it does. Why It Matters: Avoids “God classes” that block clean PRs & slow refactoring. Personal Analogy: “If you can’t give a clean commit message for the change, it’s violating SRP.” Code Smell: Method/class summary has multiple and/or. Actionable: Before adding a method, ask: “Is this a different concern?” Read more on SRP Short link: bytecrafted.dev/solid-srp O: Open/Closed Principle (OCP) Real Meaning: Add features by extension, not by editing old code. Why It Matters: Keeps legacy code stable; new business rules plug in cleanly. Personal Analogy: “If a new requirement means touching brittle switch statements, you’re not OCP.” Code Smell: Growing switch/if chains for types or behaviors. Actionable: When adding a rule, prefer new handler/class over changing the old one. Read more on OCP Short link: bytecrafted.dev/solid-ocp L: Liskov Substitution Principle (LSP) Real Meaning: Subtypes must behave as expected, no surprises for callers. Why It Matters: Swapping implementations shouldn’t break existing tests or runtime logic. Personal Analogy: “If a subclass throws where the base returns null, that’s an LSP landmine.” Code Smell: Derived classes override with different exceptions, parameters, or semantics. Actionable: Run parent class tests on every subclass; look for broken guarantees. Read more on LSP Short link: bytecrafted.dev/solid-lsp I: Interface Segregation Principle (ISP) Real Meaning: Small, client-focused interfaces, never force unused methods. Why It Matters: Reduces coupling, makes mocks/tests trivial, avoids NotSupportedException landmines. Personal Analogy: “If your interface summary needs bullet points, it’s already too fat.” Code Smell: Implementations with empty or throw NotSupportedException methods. Actionable: Extract groups of related methods into separate interfaces as soon as a client skips one. Read more on ISP Short link: bytecrafted.dev/solid-isp D: Dependency Inversion Principle (DIP) Real Meaning: Depend on abstractions, not concrete implementations, flip the usual control. Why It Matters: Makes business logic testable, swappable, and free of infrastructure glue. Personal Analogy: “If you see new SqlRepo() in a service, that’s DIP going up in flames.” Code Smell: Direct instantiation of dependencies inside business logic. Actionable: Use constructor injection for every external dependency; mock in tests, swap in production. Read more on DIP Short link: bytecrafted.dev/solid-dip Read full series: bytecrafted.dev/series/solid. ...

Async/await is powerful but overused. This guide breaks down async misconceptions, shows real enterprise use cases, and gives you a practical decision framework for async in C#.

TL;DR DIP means depend on abstractions, not concrete implementations. Use interfaces and dependency injection to decouple business logic from details. DIP improves testability, flexibility, and maintainability in C# code. Avoid leaky abstractions, unnecessary interfaces, and service locator anti-patterns. Use C# 12 primary constructors and .NET 8 DI features for clean, modern architecture. The Dependency Inversion Principle helps you turn rigid, tightly-coupled code into flexible, testable systems. Rather than depending on concrete implementations, your high-level modules rely on abstractions. This goes beyond dependency injection, it’s about changing the direction of control flow. ...