️🏗️ Design Patterns 🔧 in C# 🎭

This course teaches you battle-tested design patterns every C# developer should know — from Creational to Structural to Behavioral patterns.
We use practical C# examples with modern .NET features to show when and how to apply each pattern effectively.
By the end of the course, you’ll have a solid toolkit of proven solutions to common software design challenges you face daily.

Resources

👩‍💻 Source Code

If you are stuck, you can refer the final source code, available at GitHub Repository

Prerequisites

To follow along comfortably, you’re expected to have:

1. A compatible IDE such as Visual Studio 2026 (recommended), JetBrains Rider, or VS Code with the C# Dev Kit extension
2. Working knowledge of C# and object-oriented programming fundamentals
3. Basic understanding of interfaces, inheritance, and polymorphism in C#

flowchart LR
    root((Design Patterns))
    
    creational[🏗️ Creational Patterns]
    structural[🔧 Structural Patterns]
    behavioral[🎭 Behavioral Patterns]
    
    singleton[🔒 Singleton]
    factory[🏭 Factory Method 🚧]
    builder[🧱 Builder 🚧]
    abstract-factory[🏢 Abstract Factory 🚧]
    prototype[🐑 Prototype 🚧]
    
    decorator[🎁 Decorator 🚧]
    adapter[🔌 Adapter 🚧]
    facade[🏛️ Facade 🚧]
    proxy[🚪 Proxy 🚧]
    composite[🌳 Composite 🚧]
    bridge[🌉 Bridge 🚧]
    flyweight[🪶 Flyweight 🚧]
    
    strategy[🎯 Strategy 🚧]
    observer[👁️ Observer 🚧]
    command[📋 Command 🚧]
    template[📝 Template Method 🚧]
    state[🔄 State 🚧]
    chain[⛓️ Chain of Responsibility 🚧]
    iterator[🔁 Iterator 🚧]
    mediator[🤝 Mediator 🚧]
    visitor[🚶 Visitor 🚧]
    memento[💾 Memento 🚧]
    interpreter[📖 Interpreter 🚧]
    
    root --> creational
    root --> structural
    root --> behavioral
    
    creational --> singleton
    creational --> factory
    creational --> builder
    creational --> abstract-factory
    creational --> prototype
    
    structural --> decorator
    structural --> adapter
    structural --> facade
    structural --> proxy
    structural --> composite
    structural --> bridge
    structural --> flyweight
    
    behavioral --> strategy
    behavioral --> observer
    behavioral --> command
    behavioral --> template
    behavioral --> state
    behavioral --> chain
    behavioral --> iterator
    behavioral --> mediator
    behavioral --> visitor
    behavioral --> memento
    behavioral --> interpreter

    click creational "/courses/design-patterns/creational" "Go to Creational"
    click structural "/courses/design-patterns/structural" "Go to Structural"
    click behavioral "/courses/design-patterns/behavioral" "Go to Behavioral"

    click singleton "/courses/design-patterns/creational/singleton/" "Go to Singleton Pattern"
    %% click factory "/courses/design-patterns/creational/factory-method/" "Go to Factory Method Pattern"
    %% click builder "/courses/design-patterns/creational/builder/" "Go to Builder Pattern"
    %% click abstract-factory "/courses/design-patterns/creational/abstract-factory/" "Go to Abstract Factory Pattern"
    %% click prototype "/courses/design-patterns/creational/prototype/" "Go to Prototype Pattern"
    
    %% click decorator "/courses/design-patterns/structural/decorator/" "Go to Decorator Pattern"
    %% click adapter "/courses/design-patterns/structural/adapter/" "Go to Adapter Pattern"
    %% click facade "/courses/design-patterns/structural/facade/" "Go to Facade Pattern"
    %% click proxy "/courses/design-patterns/structural/proxy/" "Go to Proxy Pattern"
    %% click composite "/courses/design-patterns/structural/composite/" "Go to Composite Pattern"
    %% click bridge "/courses/design-patterns/structural/bridge/" "Go to Bridge Pattern"
    %% click flyweight "/courses/design-patterns/structural/flyweight/" "Go to Flyweight Pattern"
    
    %% click strategy "/courses/design-patterns/behavioral/strategy/" "Go to Strategy Pattern"
    %% click observer "/courses/design-patterns/behavioral/observer/" "Go to Observer Pattern"
    %% click command "/courses/design-patterns/behavioral/command/" "Go to Command Pattern"
    %% click template "/courses/design-patterns/behavioral/template-method/" "Go to Template Method Pattern"
    %% click state "/courses/design-patterns/behavioral/state/" "Go to State Pattern"
    %% click chain "/courses/design-patterns/behavioral/chain-of-responsibility/" "Go to Chain of Responsibility Pattern"
    %% click iterator "/courses/design-patterns/behavioral/iterator/" "Go to Iterator Pattern"
    %% click mediator "/courses/design-patterns/behavioral/mediator/" "Go to Mediator Pattern"
    %% click visitor "/courses/design-patterns/behavioral/visitor/" "Go to Visitor Pattern"
    %% click memento "/courses/design-patterns/behavioral/memento/" "Go to Memento Pattern"
    %% click interpreter "/courses/design-patterns/behavioral/interpreter/" "Go to Interpreter Pattern"

What to Expect from This Course

This is a quick reference guide, not an in-depth tutorial. Each pattern includes:

• A concise explanation of what the pattern does and when to use it.
• Practical C# code examples demonstrating the pattern in action.
• Links to a companion GitHub repository with complete, working implementations for closer examination.

Use this course to refresh your memory before an interview, quickly compare patterns when designing a solution, or grab a reference implementation when you need to apply a pattern in your project.