First, you need to observe if the slowness is specific to certain use cases or it is a general slowness. Secondly, you should analyze the pega alert logs to see if there are any alerts related to your slowness. If possible, you can rollback those hotfixes to confirm the fact it is those hotfixes that account for your slowness. Remember that sometimes there are a lot of dependent hotfixes involved, try to identify the DLs that have been applied which you suspect might be the culprits.