In the glorious future when CD has 10k+ active users, it might be a hindrance for search results to return all people whose names have a matching substring. That could be lots of extra results to wade through.

Although I agree and I'd like to see future improvements to search (in general and user search) to narrow down results, I would want to see narrowing that is:

1. Explained to the searcher.
2. A useful narrowing.

Having a hypothetical checkbox for "whole word match only" narrows down in a way that is easy to understand, and useful provided you know it's what's being used.

Having only results that match a prefix isn't useful unless you know it's happening, and ideally have checkboxes to switch between prefixes only, postfixes only, substrings, whole words only, ...

At larger scale, I think the filter approach that's been taken on other Codidact pages could work well for user search (with different filters as appropriate).

Another point to handle it would be to order the results by how well the search term matches. The exact match, if it exists, should certainly be the top result. The score for the remaining maches could then be how much of the user name matches (when typing "tri", and there exist a username "trixie", that should come before "trichoplax"). Matches that come earlier in the user name could score higher (so the when searching "tri", "trixie" coms before "matrix". Also you could make search case insensitive, but score the results after matching case (so a search for "Tri" sorts "Trick" above "trial".

Think about search engines: You don't mind getting thousands of hits if the hit you want is on the first page. And if it isn't, you are glad that you still can access further pages.

I like this approach of making a guess at what the user will want to see, but still including the rest.

@celtschk If you transfer that comment to an answer, I'd upvote it. If you don't, I'll make an answer citing you.

I ran into this same user search thing today.

Whichever one of you makes that answer, I will also upvote it.

Michael‭ Well, as I see, you've already added that post yourself. But that's OK; it saves me some (minimal) work. :-)