Will adding Shiny Server Pro servers result in a kind of “cluster”?


You can definitely build a cluster of Shiny Servers and load balance to them. The key thing is to make sure to have sticky load balancing so that future requests for a given session go back to the same server. See more in our related article on running Shiny Server with a proxy.

Configuring a server per customer is also an option, and obviously can give you a different kind of control.