Design Patterns: Enhancing Software Design and Development

3 min readJun 26, 2023

Design patterns are reusable solutions to common software design problems. They provide proven approaches that help developers build robust, flexible, and maintainable software systems. By understanding design patterns, you can elevate your software design skills and create more elegant and efficient solutions.

Why we need to use Design Pattern:

reusable in multiple projects.
provide the solutions that help to define the system architecture.
capture the software engineering experiences.
provide transparency to the design of an application.
Design patterns are well-proven and testified solutions since they have been built upon the knowledge and experience of expert software developers.
Design patterns don't guarantee an absolute solution to a problem. They provide clarity to the system architecture and the possibility of building a better system.

Types of patterns:

1. Creational

Creational patterns provide initialization mechanisms, allowing you to create objects in convenient ways.

2. Structural

Structural patterns define relationships between classes and objects, allowing them to work together.

3. Behavioral

Behavioral patterns are used to simplify the interaction between entities.

Creational:

Singleton

This restricts the creation of a class to a single instance and provides access to that single instance.

Factory

used when we have a superclass with multiple subclasses and we need to return a subclass based on input.

Abstract factory

uses a super factory to create factories, which we then use to create objects.

Builder

used to create complex objects using simple objects. It gradually creates a large object from a small, simple object.

Prototype

This Pattern helps improve performance when creating duplicate objects; instead of creating a new object, it creates and returns a clone of an existing object.

Structural:

Adapter

converter between two incompatible objects. We can use the adapter pattern to combine two incompatible interfaces.

Composite

uses one class to represent a tree structure.

Proxy

provides the functionality of another class.

Flyweight

reuses objects instead of creating a large number of similar objects.

Facade

provides a simple interface for a client, which uses the interface to interact with the system.

Bridge

Decouple an abstraction from its implementation so that the two can vary independently.

Decorator

adds new functionality to an existing object without tying it to its structure.

Behavioral:

Template method

defines a basic algorithm and allows descendants to override some steps of the algorithm without changing its overall structure.

Mediator

provides an intermediary class that handles all communication between different classes.

Chain of responsibility

It helps to build a chain of objects. A request enters from one end and keeps going from one object to another until it finds a suitable handler.

Observer

allows one object to monitor and respond to events occurring in other objects.

Strategy

allows for strategies (algorithms) to be changed at run time.

Command

an interface that declares a method for performing a specific action.

State

allows an object to change its behaviour depending on its state.

Visitor

used to simplify operations on groups of related objects.

Interpreter

defines grammar for a simple language in the problem domain.

Iterator

sequentially accesses elements of a collection without knowing its underlying form.

Memento

used to store an object’s state; this state can be restored later.

Conclusion:

Design patterns provide proven solutions to common software design problems. By applying design patterns, developers can improve code reusability, maintainability, and flexibility. Understanding and utilizing design patterns can elevate software design skills and lead to more efficient and robust solutions.

We will discuss each and every Design pattern in our upcoming Blog.