[rawnlq]

Score of past submissions on hn/reddit is a good signal.

For example to get sorted submissions by domain on reddit: https://www.reddit.com/domain/blog.codinghorror.com/top/?sor...

Similarly for HN (but not sorted): https://news.ycombinator.com/from?site=codinghorror.com

Maybe someone can automate this?

[pbnjay]

Yes! I was mainly trying to find some proxy for quality that could be easily automated, so these would be a much better start.