How do you decouple/organize a Nodejs/Express project?

I don't know if I should be saying this myself but checkout out my project specter. I have tried hard to break the application into several modules which work independently of each other. The project is quite small in terms of loc. I have not counted but I would be very surprised if it is >1000

Express makes it very easy to decouple your applications if you follow the default directory structure. All the route handlers go into the routes folder. If you have methods that are common to several routes redactor them into a common file and require them.

One other thing that I like to do is break the server.js file into config and routeConfig which contains the configuration for server and definition of routes respectively. This makes server.js more maintainable

I would say stick to the default code organization as it is pretty good.