That seems domain specific. I can imagine some services where transactions across everything are unavoidable, but I've also worked on lots of things where there's different databases and transactions aren't needed between them.
Some times it is a relaxation of requirements though. Some people might want/need account deletion to also remove all the content related to the account transactionally, etc, and if that's a requirement, everything account related must be in a transactionable system.
If you can be more flexible on that, separating account management from other data is pretty common in my experience.
Some times it is a relaxation of requirements though. Some people might want/need account deletion to also remove all the content related to the account transactionally, etc, and if that's a requirement, everything account related must be in a transactionable system.
If you can be more flexible on that, separating account management from other data is pretty common in my experience.