In those situations, does the c++ service render the xaml or provide the c# to execute to provide the xaml? Or does it provide a shared storage/events/peer resolution/info collecting. Usually a server provides something much different than a web server does
C#/XAML on the front-end could mean that .Net/WPF is rendering the XAML and wiring up the C#. The C# might do little more than handle events triggered by the user interface and update the user interface in response to events triggered by the back end.
As the potential capabilities in front-end web development increase, the differences between web development and "desktop" software development are reduced, because web developers find themselves facing more and more of the same questions software developers have always faced when dealing with distributed software architectures at scale.
My point exactly. Spas are going in that direction. "Firebase" allows them to be "serverless" sincebthey have a shared database to write to and read from
It depends. A desktop application may have a backend, like a central web service to connect to. Even if it doesn't, there is still likely to be a logical separation of layers which may or may not be in different languages (think c++ backend with a c#/xaml front end).