To this day it doesn't seize to amaze me how many companies run on python - JPMorgan, Bank of America, LinkedIn, Dropbox, etc etc etc - that's probably at least 15K devs right there. And so many more ... Makes me proud to be a python dev :)
https://code.facebook.com/posts/1040181199381023/python-in-p...
Calling scripting/shell/utility for "backend" might give wrong ideas to certain crowds who might have thought that backend is more important than front end product sensitive code that 1Billion users interact with everyday.
Other than Dropbox (well, technically they seem to move toward Go/Rust? for core critical infrastructure), I rarely see medium to big scal projects using largely Python. Instagram, while uses Python, is relatively small size shop/group of people. I don't know well how big pinterest/eventbrite.
Some BigCos are using Python for less important projects (scratching their itch maybe?)
I don't mean to disrespect the language or the community, I prefer it over other languages but after reading all Python success story, I concluded that more of them are just for morale booster for the community. 10 years large scale Python project is probably very rare...(maybe YouTube but the again the major use of Youtube is their video/streaming, non-Python)
They are now using HHVM, Hack, Reason, Erlang, C++, JavaScript, OCaml, Haskell.
YouTube has moved some of their core components to Go.
http://www.cisco.com/c/en/us/about/corporate-strategy-office... = Cisco Web & Email Security
The Source for the Server is now open source: https://github.com/ironport/shrapnel (python / cython /Pyrex)
And disqus had run mainly on Python before they moved some parts to Go-Lang
Many Gov's / Edu's run on Plone
No offense to disqus but they are relatively small.
So I believe my statement still holds true.
You are very very wrong, but I'm not violating any NDAs here
Another big elephant is OpenStack.
Or take Google for example, where Python was (still is for all I know) one of the few officially sanctioned languages: Python, C++, Java (and now Go too -- which, contrary to popular belief hasn't been some kind of exclusive language Google uses, nor has it toppled C++/Java/Python etc from their codebases).