https://www.codementor.io/ruby-on-rails/tutorial/6-ruby-best-practices-beginners-should-know
https://exercism.io/users/sign_in
https://www.rubytapas.com/pricing/
https://learnrubythehardway.org/book/ex1.html
https://www.reddit.com/r/ruby/comments/2zlcyc/tips_on_becoming_a_ruby_expert/