We are currently performing a clean up on our marketing cloud instance with 30 BUs.
Currently, we have a ssjs script that fetches all the data extensions and it's row count using the undocumented API mentioned here. The use case is to delete the data extensions that are junk/test using this method. The problem is while fetching the data extensions, we are also getting a list of System data extensions(not visible on UI). Is there a way where we can identify these data extensions, so that we can exclude them from our script? I have checked the Data Extension object and it has no field to identify this.