Handling multiple express applications

I was wondering what is the best practice for deal with multiple express applications using only one api gateway. Is it considered a good practice to put an express application under different base paths such as:
API 1 my.api.com/service-1
API 2 my.api.com/service-2

under each base path service-1 and service-2 I could deploy an express application with its router set to /
Is there any project boilerplate or doc I could follow to reach a best approach for a scalable application?