You Learned Rails...Now What?

If you have been using Rails for 6 months or more but you still feel like you could be doing a lot better...

...and if you don't feel very confident in your Ruby skills...

...and if you'd like to earn more, write better code & be proud of your work...

...this could be the most important message you'll read today.


my name is Jesus Castello & I've been a Ruby developer for over 6 years.

I've spent the last 2 years teaching Ruby & I'd love to help you become a better Ruby developer.

Most of my students feel a lack of confidence because their Ruby skills are lacking.

They just rushed their learning & are missing vital information about how Ruby works.

That's oK if you are just doing this as a hobby...

But if you want to get paid you need to take this seriously & learn more about Ruby.

Just because you can write a simple CRUD Rails app you won't impress anybody.

When you take your learning seriously...

You'll be able to write better code, enjoy your work more & be proud of what you do.

That's why I invested over 100 hours of my time to put together a resource for you...

A resource which:

  • ​Helps you build a solid foundation of Ruby skills
  • ​Bridges the gap between the fundamentals & more advanced concepts
  • Shows you the tools, ideas and examples you need to understand things better

The resource I'm talking about is Ruby Deep Dive, the book for serious Ruby developers.

It's Not Only a Book, It's a Complete Package

Ruby Deep Dive is a complete package to help you build a solid Ruby foundation, bridging the gap between the fundamentals & more advanced concepts.

This is what is included:

  • A 160-page PDF eBook
  • ​100+ Code Examples You Can Copy & Paste For Quick Learning
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    8 Printable Quick-Reference Mindmaps
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    A List of Resources to Help You Keep Growing As a Developer
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    Answers to All Your Ruby Questions Via Email

Mary Katherine



“I've been reading Ruby Deep Dive as I have time and finding it to be SUPER​​​​ helpful​​​​​.

It's exactly the 'next step' I needed after doing all the beginner tutorials. Thanks for writing it!!! :)“

Some of the things you'll discover inside Ruby Deep Dive:

  • What are blocks, procs & lambdas, how they work & how to use them for maximum benefit!
  • ​Ruby tricks, tips & advice to help you become a better developer.
  • ​How to make your Ruby programs faster
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    Why Enumerable is the most important Ruby class & how to get the most out of it!
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    One thing you need to stop doing now unless you want to look like a beginner developer
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    A review of the core Ruby classes so you aren't missing out on something important!
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    Why this "secret" Ruby class makes it possible for Ruby to have class methods (this is the key to understanding how Ruby works under the hood)
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    ...and a few other things that you will not find on your average Ruby book

Imagine being able to understand every line of code in your project...

...and learning to use the full power of Ruby so you can write better code that you can be proud of.

Ruby Deep Dive will help you do that.

Click the yellow button below & grab your copy today :)


(You will instantly receive a download link to a zip file containing the PDF of the book plus all the learning resources.)


If you don't love the book & all the included bonus content (cheatsheets, guides, support), just let me know & I will give your money back.

Table of Contents

  1. Using Pry to Learn Ruby
    • The Power of Pry
    • Where did this method come from?
    • Debugging using Pry
  2. Understanding Exceptions
    • What are Exceptions and Why They Happen
    • Understanding Stack Traces
    • Using Exceptions
    • At Exit
    • Custom Exceptions
    • Common Errors Guide
  3. Working with Data
    • Strings
      • Putting Strings Together
      • Manipulating Strings
      • Working with Characters
      • Immutability and Frozen Strings
    • Arrays
      • Let's review: What's an Array?
      • Basic Operations
      • Iterating Over Arrays
      • More Array Operations
      • The Splat Operator
      • Operations Involving Multiple Arrays
    • Hash tables
      • Using Hash Tables
      • Basic Usage
      • Iterating Over Hash Values
      • Default Values
      • Using Fetch and Merge
      • The Dig Method (new in Ruby 2.3)
    • Ranges
      • Inclusive & Exclusive ranges
      • Iterating over ranges
      • Stepping
      • Random number within a range
    • Data Serialization
      • CSV
      • JSON
      • YAML
  4. The Ruby Object Model
    • Introduction to the object model
    • Super-classes
    • The singleton class
    • Ruby Internals
    • Constants in Ruby
    • Constant Lookup
    • Ruby Method Sugar
  5. Procs & Lambdas
    • What's a block & how to use them
    • Lambdas vs Blocks
    • Closures
    • Using to_proc
  6. Understanding Require
    • Why do we need require
    • How Ruby gems are required
    • Require vs Require Relative vs Load
  7. Regular Expressions
    • Character ranges
    • Capture groups
    • LookAhead & LookBehind
    • Ruby methods for working with regular expressions
  8. Modules
    • What is a module & how it's different from a class
    • 5 different ways to use modules
  9. Enumerable
    • 3 Ruby methods everyone should know
    • How to include Enumerable in your own class
    • What are Lazy Enumerators & when to use them
  10. Using Sinatra
    • Sinatra fundamentals
    • How to write a simple API
    • Interacting with a database
  11. Performance
    • Benchmarking vs Profiling
    • How to make your programs faster
  12. Comparing Objects
    • The Comparable module
    • The spaceship operator
  13. Metaprogramming
    • What is self?
    • How do you handle undefined methods?
    • Creating dynamic methods
    • Creating dynamic constants
    • Using hooks
  14. Writing a DSL
    • What is a DSL & how to implement one

 Jay Wilburn​​​​ 

Full-Stack Developer 


"This book has helped me understand things better. And I have been able to apply those learnings into some of my work."