Can you name the main patterns used in software system design?

The main design patterns of software systems can be divided into three groups:

1. Creational Patterns — responsible for object creation:

   • Singleton
   • Factory Method
   • Abstract Factory
   • Builder
   • Prototype

2. Structural Patterns — define how classes and objects are combined into larger structures:

   • Adapter
   • Decorator
   • Proxy
   • Composite
   • Facade
   • Bridge
   • Flyweight

3. Behavioral Patterns — responsible for interactions between objects:

   • Observer
   • Strategy
   • Command
   • Iterator
   • State
   • Template Method
   • Mediator

These patterns help create flexible, extensible, and maintainable systems, solving common design problems.