When the gateway times out, it shows to the user as a "hang"

(Bug, Investigate , Priority: Critical, Test Status: Needs Testing , Reported By Bad Link: Thing 3y284oe not found, )
UX, Performance
Summary: For example, consider this page, which currently takes too long to render. This is causing the gateway to time out, but the error only shows in the browser Console -- from the user's perspective, the page just hangs forever.
At the least, the client should catch this error and display some sort of "We're sorry, this page is taking too long to load" error message.
Also, we should check what's going on on the back end, and that we're not leaving the server spinning its wheels pointlessly after this happens.