Overriding Methods in Ruby on Rails: A No-Code-Editing Approach

Recently, I installed the Writebook a Ruby on Rails app from 37signals because I wanted to publish some long essays or long-form articles about testing for developers. The installation worked like a charm, including replacing Rescue with Solid Queue and adding Solid Cable. I installed it manually, not via the once tool as I already have other projects on that specific server and did not had enough time to think how deploying it via the provided tool will affect the other projects. This means I would have to update it when an update came around manually.