Since moving to a static-site generator, I occassionally need a server backend to handle logic for me.
In one case, I use it to handle user account creation for my learning platform. WordPress stores all of the usernames/passwords, and I can use JS to make calls to it, log users in, and surface "logged in only" user content.
More often, though, I'm using it as a middle-man for API calls that require the user of keys/secrets, or return data I don't want to fully expose publicly.
Here's how it works...