Memento
Captures and externalizes an object's internal state so that the object can be restored to this state later. Supports undo and rollback operations.
Memento: Snapshots Without Breaking Encapsulation
Capturing and restoring an object state without exposing its internals.
Memento in Production: Checkpoints and Serialization
Database checkpoints, workflow state, and serialized snapshots for recovery.
Advanced Memento: Persistent Structures and Deltas
Structural sharing, delta snapshots, and time travel.
Memento: Review & Mastery Quiz
Scenario questions on snapshots, checkpoints, and history.
Free Books & Guides
Refactoring.Guru — Memento
The definitive modern guide to the Memento pattern. Clear explanations, UML diagrams, real-world analogies, and code examples in multiple languages.
SourceMaking — Memento
A comprehensive companion guide covering the Memento pattern with detailed rules of thumb, criticisms, and robust code snippets.
GoF Design Patterns — Memento
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 — Memento
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 Memento
Code examples of the Memento pattern in TypeScript, Python, Java, and more.