Is it possible to build a flow based on an objects history. For instance, if I wanted a fields to update whenever another field is changed by one specific user. How would I go about this I cannot seem to find a good solution.
Flows can now be created to launch when a record is created or edited (no more Process Builder needed). So you can make one of the entry criteria be when that record was edited by a particular user.
If you're using a sandbox, you should not hardcode the ID like I did here (even without sandboxes probably don't do it that way). Instead you should do a lookup element before this, find the user ID based on name, and then use the ID found there in place here.