See Max Simultaneous Sessions Per User

In an effort to set a reasonable sessions_per_user profile setting for shared database accounts or other non-unique account (ie. an account an application uses to log into the database for all app user activity) I'm wondering if there's a view to look at or a script someone has created to see the maximum number of simultaneous sessions a user has had over some defined period of time. Note: some database are 11.2g and others are 19c if that makes a difference, hence the different version tags.