Rails offers GlobalID feature to identify model instances in an application. This functionality is automatically included in ActiveRecord:

https://www.mateusnava.com/posts/rails-globalid
https://github.com/rails/globalid

Mongoid does not currently transparently integrate with GlobalID as ActiveRecord does. Because there is no transparent integration, we should have an example in Mongoid documentation explaining how to integrate with GlobalID.

When the documentation is written, the following should be checked:

Usage with standalone models
Usage with referenced associations
Usage with embedded associations
Usage with ActiveJob