SOLID Principles Explained: Five Rules for Cleaner, Scalable Code

SOLID is a collection of five software design principles aimed at improving code quality, scalability, and maintainability. The first principle, Single Responsibility, states that each class should have only one reason to change, avoiding so-called 'God Classes' that handle multiple unrelated tasks. The Open/Closed Principle encourages extending functionality through new code rather than modifying existing logic, while the Liskov Substitution Principle requires that child classes can replace parent classes without breaking the application. The Interface Segregation Principle advises against forcing classes to implement methods they do not need, instead splitting large interfaces into smaller, focused contracts. Together, these principles guide developers toward more deliberate planning and cleaner architectural decisions.