Electron & NodeJS Project Management

In a server environment, I expect to write URL paths to query for data. In Electron, because I can use NodeJS in any part of the application with normal JavaScript, there seems to be no 'separation' between the two.

Where should most of the code be, especially if when using NodeJS? In the main.js file, or in the application's JavasScript file? Additionally, if a result from the NodeJS code is being written to the HTML dom, should it be written directly from the same code or stored and then written in normal JavaScript?

What is normal or good practice in Electron?

via user1679669