I don't understand why sites like reddit need to do any work on (unauthd) GET. They are not instant messaging platforms, they are forums. You can live with a ~1-2-5 minute delay on forums. So POSTs (from logged in users) append to a queue, and a worker does work at regular intervals, creates the HTML and that gets sent to a cache + distributed to a CDN if needed. There's no need to do work on unauthd GETs for a forum.