It's my fondest wish that we find more uses for #fediverse and make inventive ways of using the ActivityPub protocol.
I've mentioned the event/calendar idea before. But I'd also like to see a jobs site, with tools specifically designed around that activity.
Maybe like this:
It's done already: https://cupid.careers lets you follow @thecupid and get job listings and polls that are used to figure out other potential co-workers...