But doesn't that just put you right back into RPC-land, where you don't even know whether a method call is local or over the network, because the interface is t

But doesn't that just put you right back into RPC-land, where you don't even know whether a method call is local or over the network, because the interface is the same? And if you take the suggested alternative of wrapping the return values in 'Future', then your interface just changed, so now the code that calls your service all needs to be rewritten. It's pretty well established that service calls are either local or remote, and the service interface should show the difference between the two, but that means means that changing a service from local to remote is always going to break its clients. That's a pain point, but it's probably better than making every service call remote by default which is what a microservices architecture does.