I see that on math.SE and meta there's a new tab labeled 'Jobs', but it just directs to "Page Not Found". What's that for? Is there a new feature that's not working correctly yet?
It's fresh evidence that people should not be deploying updates on Friday afternoons.
The tab was added to Stack Overflow as a way to tie SO Careers with the Q&A site. Its presence on all other sites is surely a bug. Expect the Jobs to disappear shortly.
A more thorough explanation just came by way of developer Adam Lear, who retweeted this a moment ago.