Software Design Patterns: Building Flexible, Maintainable & Scalable Systems Software design patterns are proven, reusable approaches to solving common software design problems. Instead of reinventing a solution every time, developers can use a well-understood pattern. The major patterns can be understood in three broad groups: 1. Creational Patterns How should objects be created ? These patterns deal with object creation, making the system more flexible and reducing dependency on specific classes. Factory Method - Creates objects through a common interface while allowing the actual implementation to be chosen at runtime. Abstract Factory - Creates families of related objects without specifying their concrete classes. Builder - Constructs complex objects step-by-step, particularly useful when an object has many optional properties. Prototype - Creates new objects by copying or cloning an existing object. Singleton - Ensures that a class has only one instance and provides a common ...