There are some very good reasons to use Rails. In the case of this article I am using the RailsAPI gem which is a very thin version of Rails itself. The README

There are some very good reasons to use Rails. In the case of this article I am using the RailsAPI gem which is a very thin version of Rails itself. The README goes into details on why use this rather than a more simple solution https://github.com/rails-api/rails-api https://github.com/rails-api/rails-api