I'm not super familiar with Verta.AI but reading about their product it seems pretty different. I read Verta.AI as a model deployment and tracking solution. Seldon would be the opensource comparison that immediately comes to mind. Pachyderm is more of a general pipeline and data version control system. You can do some very basic model deployment and tracking in it but we general recommend people use an external system such as Seldon and even have some published examples of how to integrate the two.
Disclosure: I founded Pachyderm.