Stop using Rails
Start owning it

Don't get stuck in the framework ever again. Learn to dive into the source code of Rails on your own to debug, explore, extend and master it.

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Are you struggling with Rails? Still relying on tutorials to develop your app? Working on a big ball of mud that was once a beautiful and simple Rails app? Are you starting to hate Rails and its magic? I feel your pain. I've experienced it myself and have worked with many people who struggle just like you.

This is why I created this course. It is based on my ten years of experience with Rails. It has helped more than a thousand developers and has been running for more than five years. The course uses a unique approach that will help you master Rails faster and keep doing so for all the future versions of the framework to come.

Ready to start Owning Rails?

« Fixed a bug because I knew how to deep dive into Rails source.
Learned the techniques in Owning Rails class [...] »

Gavin Miller via Twitter

The Teacher

Taught by Marc-André Cournoyer, creator of Thin

I've been developing Rails apps for the past ten years. While I was in love with Rails at first, things started to go south after working on bigger apps that soon grew out of hand and out of the bounds of Rails.

It took me a few years, but I finally mastered the framework after studying its source code and extending it.

But it won't take you as long! Because I've packed my years of experience, research and struggle into this course.

I've been teaching this course online and in-person for more than five years. I've improved, polished and perfected my approach all along. The course you see today, is the culmination of all this work.

Marc-André Cournoyer ·

I've been helping companies and people master the Rails framework for the past five years. Previously, I created Thin, one of the most popular Ruby web server, used at Heroku, Apple, VMWare. I also created my own Ruby implementation: tinyrb, because ... why not?


Join the 1000+ Rails developers who have taken this course


Some of the things you'll learn in this course

  • Understand the inner working of Rails by building a mini-version of Rails, from scratch.
  • Did you ever bang your head on a bug only to find out days later it was a Rails bug? I will teach you to read Rails code to discover bugs in minutes instead of days.
  • You'll be able to discover Rails hidden features such as core extensions, ActiveModel, custom validators and form builders by quickly skimming over its internal code.
  • Never get stuck in the framework again. Make Rails do what you want by altering its internals.
  • Write concise and reusable Rails code by understanding all the features it offers.
  • Learn how to quickly find your way in the source code of any gem.
  • Refactor your app into something you're proud of, using only the features of Rails.
  • Understand the path of a request in Rails, how your code is loaded, how views are rendered, and much more ...

After this course, NO MORE ...

  • browsing StackOverflow to debug your app.
  • relying on tutorials to do anything.
  • getting stuck in the framework.
  • thinking Rails is magic.
  • hating Rails!

« The course was fantastic, it really changed "wow [this] is magic" into "it’s not magic, I know how it works and I can find the code that makes it happen". »

Dave Harris

Who is it for

What you need to know before taking this course

You should take this course if ...

  • You have created a Rails app before.
  • You know what a Rails model, controller, helper and view is.
  • You're wondering how Rails work inside.
  • You feel Rails has too much magic.
  • You sometimes feel stuck in the framework.
  • You want to contribute back to Rails.

You should NOT take this course if ...

  • You are getting started with Rails or Ruby.
  • You don't know what a Rails controller, view or model is.
  • You have never created a Rails app on your own.
  • You want an easy and casual course. This course is intense!
  • You don't like to write code.
  • You are David Heinemeier Hansson.

Still not sure what is required to take this course? Drop me a line.

Course Content

The result of five years of improvements. 7h+ of content with plenty of exercises

Introduction — 6 videos, 1 exercise

Get ready to own Rails! Brush up your Ruby. Discover the architecture of Rails and understand the basic structure of a Gem.

ActiveRecord — 7 videos, 2 exercises

Learn how ActiveRecord loads the data into your models, how queries are constructed and how to explore its source code on your own.

ActiveSupport — 3 videos, 1 exercise

The supporting library of Rails. Explore the core extensions and utilities. Rebuild the automatic loading of files (why you never have to require).

Railties — 3 videos, 1 exercise

The glue that holds the components together and makes everything just work.

ActionController — 6 videos, 2 exercises

The core of your controllers. Discovers all the features it has to offer and rebuild two of them: before_action and redirect_to.

ActionDispatch — 8 videos, 2 exercises

Discover Rack and explore how Rails interact with the web server. Rebuild the middleware stack of Rails and its famous router.

ActionView — 5 videos, 1 exercise

Discover all the view helpers available in Rails. Rebuild view rendering with layout and URL helpers support.

ActionCable — 8 videos, 2 exercises *

Master this new component of Rails. Rebuild the websocket-based architecture that sends real-time updates to the browser.

12 Ways to Refactor Your App *

Learn the techniques to refactor your Rails app like a pro. Without using any gems, only Rails features.

Cheat-sheets — 5 PDF pages *

Summarizing important points from the course, for quick reference while coding your apps and a summary of the 12 ways to refactor your app.

Slides — 12 PDFs

The slides used in the lecture videos to help you follow along and take notes.

Code — Mini-Rails

Source code of our re-implementation of Rails. You can re-use, abuse, share and do whatever with it.

Rebuild a server — 2 videos, 1 exercise *

Rebuild three different versions of a Rack-based Ruby web server from scratch. One based on Unicorn, Puma and Thin. (Recording of live class).

Bonus Create a language ebook *

The book that helped create CoffeeScript. Why stop at mastering the framework when you can master the whole language?

* Not included in the Basic Package

Love it or it's free

If after taking this course you don't feel like you're getting your money's worth or that this course is right for you, let me know within 30 days and I'll give you your money back and you keep everything.

This course has already helped more than 1000 developers, but if it doesn't work for you, it doesn't work for me. There is no risk for you in trying.

« Owning Rails course is really good. Anyone who is looking to dig deeper in Rails should take this course. It has made me realize that Rails is not written by aliens, just by people like you and me. »

Rahul Trikha


Something for all budgets

Basic Package — $179

  • 38 Basic Owning Rails videos — 4h45
  • 10 exercises & solutions
  • Code of Mini-Rails
  • Slides

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Complete Package — $229

  • 38 Basic Owning Rails videos — 4h45
  • NEW 8 ActionCable videos — 1h
  • 13 exercises & solutions
  • Code of Mini-Rails
  • Slides
  • Rails Cheat-sheets
  • 12 Ways to Refactor Your App video — 25min
  • 12 Ways to Refactor Your App cheat-sheet
  • Rebuilding a Web Server videos — 1h
  • Create Your Programming Language ebook
  • Free updates for a year

Buy Now

Team Training

The fastest way to level up your entire team.

  • Five live & interactive sessions
  • Customized content
  • Exam & certification

Contact Us


« Am I ready to take this course? »

If you're starting to struggle with Rails, feel like it's too magical, or wondering how it works inside, you're ready! If not, get more experience by creating more apps until you start feeling the pain.

« What version of Rails are you using? »

The course currently uses Rails 5. It will be updated to Rails 6 later this year. But changes will be minimal. Because, almost everything shown in this course is applicable to any Rails version. In fact, most of what this course teaches hasn't changed since Rails was first released. You won't have to re-take this course every time a new version of Rails is released.

« Do you offer discounts? »

I offer group discounts if you purchase more than four packages at a time. I also offer educational discounts to students and residents of developing countries. Contact me to request a discount.

« Will Owning Rails help me do X? »

Owning Rails won't magically solve all your problems or give you all the solutions. But, it will show you how to find the solutions on your own.

« How is this course different from others? »

« Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime ». While most courses and tutorials feed you the answers, Owning Rails will teach you how to find the answers yourself.

« What if it doesn't work? »

I refund you. No questions.

« Marc is a very talented guy. This class is a must if you want to understand how Ruby on Rails works and improve your performance when coding apps. Worth every single peny »

Mauro Morales

Still got some questions? Drop me a line.