Event Sourcing
Stores the state of a system as a sequence of events rather than the current state. Enables full auditability, time travel, and complex event processing.
Event Sourcing: The Log Is the Truth
Storing every state change as an event and deriving state by replay.
Event Sourcing in Production: Streams and Snapshots
Event stores, snapshots, and versioned streams at scale.
Advanced Event Sourcing: Projections and Sagas
Projections over streams, sagas coordinated by events, and the full picture.
Event Sourcing: Review & Mastery Quiz
Scenario questions on the log, snapshots, and projections.
Free Books & Guides
Refactoring.Guru — Event Sourcing
The definitive modern guide to the Event Sourcing pattern. Clear explanations, UML diagrams, real-world analogies, and code examples in multiple languages.
SourceMaking — Event Sourcing
A comprehensive companion guide covering the Event Sourcing pattern with detailed rules of thumb, criticisms, and robust code snippets.
GoF Design Patterns — Event Sourcing
The original Gang of Four book describing the pattern. Available in the "Design Patterns: Elements of Reusable Object-Oriented Software" on Wikipedia.
Official Documentation
Refactoring.Guru — Event Sourcing
The definitive modern guide to the Event Sourcing pattern. Clear explanations, UML diagrams, real-world analogies, and code examples in multiple languages.
Wikipedia — Event Sourcing Pattern
Wikipedia article explaining the Event Sourcing pattern with examples and history.
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 — Event Sourcing
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 Event Sourcing
Code examples of the Event Sourcing pattern in TypeScript, Python, Java, and more.