[takeda]

I'm not sure where you got this from. There's nothing inherent in WSGI that prevents you from spawning multiple threads and processes. I'm unaware of WSGI implementation that does not do this. uWSGI even shows how to do this even in their quickstart [1].

Having said that, this is actually irrelevant when trying to scale out. There's nothing that prevents you from starting your application multiple times each copy on a different machine. As long as your application is stateless (which is a requirement no matter which language you use). I don't think there's any programing language which prevents you from doing that.

[1] http://uwsgi-docs.readthedocs.io/en/latest/WSGIquickstart.ht...