How to deploy/build a project on multiple frameworks?

Question

Express.js

Good afternoon. Express has not yet been studied, so the question may be stupid, but still it arose. Both IDE and npm offer to deploy one project for one framework, for example, only for vue. How to later combine this project with a backend written in express? Or, for example, django.
And the quest bonus. :) How can I use a ready-made layout in a new vue project? Rewrite again, breaking into styles and templates in each specific module? Because as far as I know, it's bad form to simply include the vue library via cdn.

Answer 1

1. RESTful
2. It's better to use a assembler - webpack, to connect the layout you will have to spread everything beautifully according to templates