From what I heard (I never had so many devices to manage myself), Salt can scale nicely when managing a very large number of devices - see for example this story from LinkedIn: https://s.saltstack.com/saltstack-at-web-scale-better-strong.... However, they're using it in the "classical" topology which is agent based. For non-agent base, you may consider looking into Salt-SSH: https://docs.saltstack.com/en/latest/topics/ssh/. Hope this helps!