I also built my first startup in python. It was a technical success (and a financial failure) but using it imply a few things :

* good coders. ( bad coders can do much more damage. )

* you need to use cython (and maybe numpy).

* memory profiling is hard

* you need to search pypi alot, there is likely something there to help you.

* windows builds of extensions can be tricky.

I am also concerned about its future, the community seems in a "I know better than you" attitude and I don't see anything major coming, except pypy.