I have been struggling to know why my back end files are being loaded as front end files.
As I am working a new project with angular+node+gulp, it seems a bit confusing for me.
Here goes an image with the exceptions..
It's impossible to answer your question in a current form.
<script> tag in your HTML. Maybe you are concatenating and minifying more than you need - not only frontend but also your backend files, and they end up being bundled together.