Hi Luciano,
Putting a MERN app in production requires knowledge of each component in the stack i.e. MongoDB, Node, React. MERN app is just like any other web app and needs some special attention before production usage. As you said, things like minification (and concatenation) of scripts/CSS and putting them in CDN is necessary. Here are a few links that should help you understand various production checklists :
MERN, being a starter app, doesn't have any clear set of guidelines about how one should deploy in production. In the end it's a web app - You should follow the general best practices that apply to deploying web apps.
Hope this helps!