You're also using Flask? I wrote a short piece about roughly the same subject as the author of the original article uses for Django. Running Flask behind gunicorn and nginx, monitored by supervisord:
Yes, using Flask. I need to write why we chose it over Django....but mostly becasue we're using Mongo and once you're down the path of not using the Django ORM, what's the point? Also, it seems like there's dozens of articles on "how to structure" your large Django projects, so you don't even get good guidance about it out of the box.
I'm running mine under NGINX->uWSGI....but might be switching to Gunicorn. (I'm still researching our path to production).