Software Design
Dependency Inversion Principle: Depend on What Matters
The Dependency Inversion Principle (DIP) closes out SOLID, and it’s the one that quietly decides how painful your codebase feels as it grows. At its core, DIP says: High-level …
Interface Segregation Principle: Stop Forcing Clients to Care
The Interface Segregation Principle (ISP) is the “I” in SOLID, and it boils down to a simple idea: A client shouldn’t be forced to depend on methods it doesn’t use. In other words, …
Liskov Substitution Principle: Don’t Surprise Your Callers
The Liskov Substitution Principle (LSP) is the quiet backbone of safe inheritance. It’s the “L” in SOLID, and it answers one simple question: If I swap a base class instance with a …
Open-Closed Principle: Extend Without Breaking Things
The Open-Closed Principle (OCP) sits second in SOLID, but it’s usually the one you feel when requirements start shifting under your feet. The idea is captured in a single sentence: …
Single Responsibility Principle: Why One Job Is Enough
There’s a simple sentence that quietly transforms how you write software: A class should have only one reason to change. That’s the Single Responsibility Principle—the “S” in …