[EN] How I upgraded my pet project from Rails 7 to Rails 8 in 30 minutes

I have a custom/ folder in my project where I keep files that I change instead of modifying generated files. The only change in generated files is customization loading. As a result when I need to upgrade a project I overwrite default files with bin/rails new and add a few require "custom/file.rb" statements. Since Rails 8 will be released soon I decided to test my custom application layout and upgrade prototype I use for my pet projects from Rails 7 to Rails 8. I will go over the whole process step by step and maybe customization that made it easy will become one you’d like to try yourself. The only feature application has is an authentication with devise so I (almost) did not have any issues with app functionality or changes introduced in Rails 8.