The projet layout is the following:
src
│ app.js # App entry point
|----api # Express route controllers for all the endpoints of the app
|---routes
|----config # Environment variables and configuration related stuff
|----jobs # Jobs definitions for agenda.js
|----loaders # Split the startup process into modules
|----models # Database models
|----services # All the business logic is here
|----subscribers # Event handlers for async task
This project was inspired on: bullet-proof-node-js