Is it good practice to run a backend and a fronted server with express in NodeJS?

i am currently working on a simple NodeJS/AngularJS application and my current project looks like this:

/frontend/index.html <-- AngularJS home page
/frontend/js/app.js  <-- AngularJS app.js
/backend/package.json<-- NodeJS package.json
/backend/index.js    <-- NodeJS script

and I am only serving the backend API with my NodeJS express server while I open the frontend part directly (file://.../frontend/index.html) in my browser.

Is it good practice to serve both the "Backend API" and the frontend with NodeJS (e.g. with two express instances running) and how would I organize the code?

via daG