System Design Primer

https://github.com/donnemartin/system-design-primer

Rails - how to disable all console logging?

https://stackoverflow.com/questions/17203529/rails-how-to-disable-all-console-logging

Rails podcasts

https://www.johnnunemaker.com/

Upgrading Rails

https://www.typeerror.org/docs/rails~5.0/guides/upgrading_ruby_on_rails