How to quickly familiarize with any legacy Rails app

Ruby on Rails is a mature technology, and probably that’s why many people say that it’s a dead technology. But it’s not. Fewer developers start new projects with Rails, but hundreds of thousands of applications are in the maintenance mode. This is the reason why the skill of quickly adapting to the legacy code is so essential for you as a Rails developer.Joining the legacy project is not easy, and the reality might overwhelm you if the documentation is not well-maintained (which is the case in many projects). That’s why I decided to create a list that would help you familiarize the business logic of the legacy application made with Rails.Thanks to this list, I successfully joined several dozen legacy projects and started effective development from day one. Here is the list.