Web applications.
If there is a chance - any chance - that you have a random web application that you might hit more often than ten times an hour, do yourself a favor and stick it behind a caching proxy of some kind, like Nginx.
If there is a chance - any chance - that you have a random web application that you might hit more often than ten times an hour, do yourself a favor and stick it behind a caching proxy of some kind, like Nginx.