If you have services with even a few users you should set up LDAP (openldap is fine) and then experiment with it.
LDAP is pretty old and very well supported overall. At one point I configured ldap for postfix virtual hosting. I chose LDAP rather than a database backed solution because of widespread first class support everywhere. The same directory later enabled me to use a ton of other things including SSO. You're always finding new ways to use it once you have it.
It's a great skill to have and is nowhere near as complicated as people make it out to be, including live replication.
LDAP is pretty old and very well supported overall. At one point I configured ldap for postfix virtual hosting. I chose LDAP rather than a database backed solution because of widespread first class support everywhere. The same directory later enabled me to use a ton of other things including SSO. You're always finding new ways to use it once you have it.
It's a great skill to have and is nowhere near as complicated as people make it out to be, including live replication.