I've been working together with the guys @ Lacerba for over two years. Lacerba is the biggest online school in Italy. Prior to working together they were running their school off a CMS platform called Teachable that, however, was starting to feel a little limiting.
This is when we started working together on what now is Lacerba.io. A full-fledged online school built using Ruby on Rails in the backend and Vue.js in the frontend.