Every event in YouTrack — creating, deleting, updating a user account, project, service and so on — is logged and stored.
To review updates to your YouTrack instance, select Audit Events in the Server Settings section of the Administration menu. The target links provide access to the entities that are managed in Hub.
You can also download information about any event as a JSON file for further investigation. To do so, select one or several events in the list and click the Download as .json button.