Not Invented Here: Things Rails Didn't Innovate

Introduction

"Not Invented Here: Things Rails Didn't Innovate" by Caleb Hearth at RailsConf 2025 explores how Ruby on Rails (Rails), while known for innovation, is deeply rooted in foundational software design patterns and concepts developed by others. The talk highlights key elements Rails is famous for, but did not originally invent, demonstrating how iteration and adaptation drive successful frameworks.

Key Points

Model-View-Controller (MVC):
- Originally developed by Trygve Reenskaug in 1979 at Xerox PARC, not by Rails.
- Early MVC concepts differ from Rails' implementation, such as how views and controllers interact, and the use of editors.
- Rails' structure (app/models, app/views, app/controllers) closely follows the MVC pattern but adapts it for web development.
REST (Representational State Transfer):
- Concept formalized by Roy Fielding in his 2000 Ph.D. dissertation.
- REST predates Rails, but Rails helped popularize RESTful patterns (such as the seven default routes: index, show, new, create, edit, update, destroy).
- Rails' approach encourages stateless communication and standardized resource routing, influencing many other frameworks.
Convention Over Configuration:
- Principle promoting sensible defaults over manual configuration, allowing quicker setup and less boilerplate.
- While Rails and Java's Spring Boot popularized this principle, the idea traces back to Eric S. Raymond, Rob Lanphier, and even the "law of least astonishment" from older programming texts.
- Rails’ generators and assumed naming patterns exemplify this philosophy.
Active Record Pattern:
- Martin Fowler introduced the Active Record pattern in 2003, just before Rails’ official release.
- Rails’ Active Record gem extends the pattern to include validations, callbacks, and type mapping; though it occasionally blurs lines with other patterns like Data Mapper.
- The gem's adoption led to conventions and some criticism (e.g., "God objects").
Merb Framework and Rails 3:
- Merb, a modular Ruby framework developed as a "clean room" rewrite of Action Pack, contributed key ideas to Rails.
- In 2008, the Merb and Rails teams merged, leading to the more modular, extensible Rails 3.
- This transition enabled public APIs, plugin extensibility, and broad improvements in Rails' architecture and performance.

Illustrative Anecdotes and Reflections

The speaker shares personal reflections on influential community members, such as Sandi Metz, Katrina Owen, and why the lucky stiff, and how their contributions and ideas impacted the Ruby community.
The practical impact of these rules and philosophies is discussed, such as guidelines for maintainable code and the personal benefits of learning from established best practices.

Conclusion & Takeaways

Rails' strength lies not in inventing core programming concepts, but in skillfully integrating proven ideas to create a productive web framework.
Understanding the origins and evolution of these key ideas enriches developers and advocates for building on the accumulated wisdom of the software community.
Developers are encouraged to learn from and iterate on the best ideas, just as Rails did, ensuring lasting success and maintainability in software projects.

Not Invented Here: Things Rails Didn't Innovate
Caleb Hearth • Philadelphia, PA • Talk

Date: July 10, 2025
Published: July 23, 2025
Announced: unknown

Rails is a mixture of design patterns, practices, and magic. In this talk, we'll explore how Rails embraces ideas from other frameworks and projects.

Active Record was born of Martin Fowler. MVC was the brainchild of Trygve Reenskaug. Rails 3 completely absorbed the Merb project, gaining modularity and extensibility that it previously lacked.

We all learn by standing on the shoulders of giants, even Rails. By understanding the inception of design patterns, we are more likely to be able to create ideas of our own. This helps us to not only grow in our own ability, but to help others improve as well.

RailsConf 2025