When hosting a Python web app in production you can’t get around using a WSGI server and a web server. Gunicorn and Nginx are solid and popular options - but what are those two apps? Why do people run both, and not just one of them? Nginx and Gunicorn work together Nginx is where requests from the internet arrive first. It can handle them very quickly, and is usually configured to only let those requests through, which really need to arrive at your web application.