The project itself is a great concept but pushing people into RoR and jQuery? Really? Come on, it's 2017. Ruby is hardly a marketable skill, there are very few agencies still utilising it on new projects. I'd also be shocked to see a new project built with jQuery in this day and age.

Teach beginners backend JavaScript with Node.js. It's not a matter of personal preference, JavaScript is objectively easier for beginners to learn and utilise for backend programming because arbitrarily introducing another language when they already know front-end JS increases cognitive load for no benefit.