Your backend and frontend folders are already separated in your Laravel app. Anything inside your public folder is inside the public domain and anyone using the website has access to those files. Anything other than the public/ folder is your backend. Laravel follows a common MVC architecture for web frameworks.

So any files you want users to have direct access to (js, css, etc) go into this public folder. On the other hand if you have any frontend type files that need compiling for example blade views, or SASS or LESS files or your Coffee script. Well that goes into your resources/ directory.

Side note: the public folder is inside the root of the project, not inside the app/ folder where the heart of your project should live (but really it's up to you).