Singleton
Ensures a class has only one instance and provides a global point of access to it. Commonly used for logging, driver objects, caching, and thread pools.
Singleton: One Instance, One Access Point
Ensuring a class has exactly one instance and a global access point to it.
Singleton in Production: Pools and Registries
Connection pools, caches, and registries as legitimate singletons — with injection.
Advanced Singleton: Multiton and Lifecycle Managers
Multitons, managed instances, and why the pattern survives only where scoped.
Singleton: Review & Mastery Quiz
Scenario questions on instances, scoping, and lifecycles.
Free Books & Guides
Refactoring.Guru — Singleton
The definitive modern guide to the Singleton pattern. Clear explanations, UML diagrams, real-world analogies, and code examples in multiple languages.
SourceMaking — Singleton
A comprehensive companion guide covering the Singleton pattern with detailed rules of thumb, criticisms, and robust code snippets.
GoF Design Patterns — Singleton
The original Gang of Four book describing the pattern. Available in the "Design Patterns: Elements of Reusable Object-Oriented Software" on Wikipedia.
Official Documentation
Video Courses
freeCodeCamp — Design Patterns Course
A comprehensive multi-hour video course covering all major design patterns with implementations in JavaScript and TypeScript.
Design Patterns in Modern JavaScript Playlist
YouTube playlist covering creational, structural, and behavioral patterns with clear code walkthroughs.
Web Dev Simplified — Singleton
Clear, concise video tutorials covering design patterns with practical examples.
Practice & Examples
Awesome Low-Level Design (GitHub)
A curated collection of free LLD resources, pattern implementations, and interview problems across multiple languages.
Design Patterns Implementation (GitHub)
The most popular open-source collection of design pattern implementations with detailed explanations.
Refactoring.Guru Examples in Singleton
Code examples of the Singleton pattern in TypeScript, Python, Java, and more.