Isn't this essentially what search engines do? Ie. Google's Page Rank.

It doesn't really seem very AI-ish except maybe for some NLP. Otherwise it's very straightforward indexes and catelogues.

I used to work at a company that used Elasticsearch to catelog and group articles and small snippets. I'm currently working at a company that's using Algolia to do something similar.

Not really what I had in mind, to be honest. I mean, yes, you can search by keyword, but I was thinking of it being more like a research assistant.