It's searchmysite which searches the indieweb (aka a wide collection of personal blogs). I was aware of indieweb, but it is only through this engine that I've started to take advantage of it and really fine-tune my ability to find like-minded blogs. Previously, I had to rely on appending blog to my searches or sticking to subreddits.

It's very good. I legitimately have had to stop searching for my interests for the time being as my RSS feed has ballooned to +1000 unread articles. Give it a shot and let me know how it goes for ya