We built a "Yelp for Colleges" product several years ago. The product needed a unified search where students could search for either a course or a college or a question from the forums with typeahead / autocomplete to get them to where they wanted to go quickly, with support for misspellings.

In all there were about 50k documents, and we mostly cared about the title field. Elasticsearch would randomly bloat up to occupy a huge amount of RAM. Restarting it would make it work for a few days. It would also occasionally crash.

We got rid of it and went with some levenshtein distance based database query

I'd love to use it again sometime but the experience was not good, and Googling for information brought up all kinds of very complex use-cases shared by others