Why would you use an integer primary key and a public facing UUID? That seems like it's the worst of both worlds: ugly externally visible identifiers, record bloat, a database that you can't easily merge in the event of backups or DR, and having to roundtrip to the DB before you know the ID of a record.
I personally stick to UUIDs in pretty much all cases, with the exception of where there are justified and benchmarked performance reasons not to.
I personally stick to UUIDs in pretty much all cases, with the exception of where there are justified and benchmarked performance reasons not to.