These are my personal RoR references/documents/tutorials I found during my RoR learning period(this is still going on...)
Rubocop A Ruby static code analyzer, based on the community Ruby style guide.
ruby-style-guide A community-driven Ruby coding style guide.
fast-ruby Writing Fast Ruby 😍 -- Collection of Common Ruby idioms. fasterer Don't make your Rubies go fast. Make them go fasterer.
peel Take a peek into your Rails applications.
brakeman A static analysis security vulnerability scanner for Ruby on Rails applications.
bullet Help to kill N+1 queries and unused eager loading.
rails_pannel Chrome extension for Rails development inspection.
reek Code smell detector for Ruby.
bundler_audit Patch-level verification for Bundler
pg_search pg_search builds ActiveRecord named scopes that take advantage of PostgreSQL’s full text search
rubycritic A Ruby code quality reporter
traceroute A Rake task gem that helps you find the unused routes and controller actions for your Rails 3+ app
rack-timeout Abort requests that are taking too long
RubyWeekly By Peter Cooper. Weekly video, tools, news about what is new and trending in the Ruby community and the language itself.
RubyDaily By Nick Kugaevsky. News and posts related to the Ruby community and programming in this language.
GreenRuby Blog posts related to Ruby in the mail to the latest gems releases, podcasts episodes, educational tools and videos (from lectures or tutorials).
RubyFlow The Ruby and Rails community linklog.
APIsOnRails Building REST APIs with Rails.
RubyTapas RubyTapas is for the busy Ruby or Rails developer who is ready to reach the next level of code mastery. Short, focused screencasts twice a week will introduce you to a wide variety of intermediate to advanced Ruby concepts and techniques, Object-Oriented design principles, testing practices, refactoring skills, and much more.
link TL;DR After introducing what complexity is, how it can be measured, and how to monitor it in Ruby - I'll get to the difficult part: how to reduce it in Ruby. The post is concluded with some thoughts and recap.
[link] (https://medium.com/wolox-driving-innovation/activerecord-postgresql-materialized-views-9a9ef56b5a8d#.grqywcf05) ActiveRecord + PostgreSQL Materialized Views
[link] (https://www.sitepoint.com/speed-up-with-materialized-views-on-postgresql-and-rails/) Speed up with Materialized Views on PostgreSQL and Rails