"Patch management is the process of using a strategy and plan of what patches should be applied to which systems at a specified time." — Wikipedia
Here's how to update the Digital Ocean droplet, including nginx:
ssh email@example.com add-apt-repository ppa:nginx/stable aptitude update aptitude safe-upgrade service nginx restart
So far we run this whenever someone on HackerOne notices that we're out of
date, which is actually harder to depend on now that we don't leak the version
Server header or error pages.