I sorta have my own personal version of this. A script that goes through the firehose on https://hnrss.github.io/ and runs everything through an LLM to filter down to things I'm interested in which then end up in an RSS feed I'm subscribed to. It works fantastically. I'm not interested in popularity though, just the items, because a lot of great stuff gets submitted to HN that never gets anywhere.

For Hazumi News on iOS I allow users to anonymously opt into keywords they are interested in and perform basic string matching on new posts on an hourly basis to determine who to notify.