LLD Object-Oriented Design: Interfaces & Abstract Classes (Designing Contracts)
Saras Growth Space
After understanding composition, inheritance, and polymorphism, the next important step is learning how to define clear behavioral contracts between components. This is where interfaces and abstract classes become essential. They help answer one of the most important questions in system design: “What should this component be capable of doing?” without tightly coupling the system to a specific implementation. Why Contracts Matter in System Design In real systems: multiple implementations exist co