Layered Design for Ruby on Rails Applications

Transition from Rails' traditional MVC trio to layered abstractions with state machines, workflows, and AI integrations and evolve your codebase into a flexible, future-ready application

Key Features

Understand Rails' architectural patterns, their strengths and limits
Organize business logic in Rails apps when the default MVC approach is insufficient
Introduce abstractions to integrate and manage AI features effectively
Purchase of the print or Kindle book includes a free PDF eBook

Book DescriptionRuby on Rails accelerates web development with its convention-over-configuration principle and model-view-controller (MVC) pattern. But as your app grows, that simplicity can turn into tangled complexity, making it harder to maintain and extend. The second edition of Layered Design for Ruby on Rails Applications helps you tackle this challenge head-on, guiding you toward a more scalable and maintainable architecture.
Written by a seasoned software engineer and open-source contributor to Ruby and Rails, this updated edition refines the proven techniques from the first edition and introduces timely new topics that reflect today's development challenges. You'll dive deeper into state machines and workflows, learning how to identify, embed, and eventually isolate them for clarity and resilience. You'll also explore the exciting frontier of abstractions in the AI era, treating LLMs as APIs, structuring agent layers, and integrating third-party libraries to keep your AI features organized and testable.
By embracing layered abstractions, you'll not only reduce complexity but also improve your ability to adapt to change - whether adding new features, scaling systems, or weaving AI capabilities into your applications.
By the end of the book, you'll be equipped to design Rails applications that remain clean, extensible, and future-ready.What you will learn

Get to grips with Rails' core components and its request/response cycle
See how Rails' convention-over-configuration shapes development
Explore patterns for flexibility, extensibility, and testability in Rails
Identify and refactor Rails anti-patterns for improved maintainability
Implement patterns for taming bloated models and messy views
Transition from implicit to explicit state machines and workflows
Treat LLMs as APIs and extract agent layers for AI-powered features
Use third-party libraries and RAG strategies to manage AI context effectively

Who this book is forThis book is for Rails developers who want to manage and master the growing complexity of their applications. Whether you're extending an MVP into a robust system, scaling a monolithic app, or exploring AI-driven features, this book equips you with the design patterns and abstractions to keep your codebase future-proof. A solid understanding of Rails principles is required, and prior experience building Rails apps will help you put these patterns into practice.