I wanted to understand how rails worked from the inside out, so I built a basic version. This is based on Active Record Lite (https://github.com/buddylamers/active_record_lite)
I build a stripped-down and basic version of rails functionality with the bare minimum to make a website:
Controllers Whitelisted Params hash Session Cookie Router WEBRICK server
I learned how ApplicationController renders and uses sessions, how to parse params with regular expressions, and in general a lot more about how Rails works.
I feel like I am able to better use Rails after this project.
If you're feeling extra fancy you can run guard!
just type guard