Ask HN: Full-content index sites? (recently posted)

Looking for the full-index search tool for _content_ of sites linked on news.ycombinator.com. I've searched hn.algolia.com extensively, but can't quite sift through the noise of other posts. (It turns about all the keywords: machine learning, index, hacker news).

What are the two hn, full-content-indexing sites (.ml domains, I think) that were recently posted to hn?

Once I find the full-text index, I'm looking for an article (3-7 years old) about one man who balances turbine blades for ~MW steam generators by hand, in his backyard in southern appalacia.