A couple days ago I updated https://search-lemmy.com/ to 0.4.0.

New features, that several people were asking for:

• The UI has been overhauled and it should be much easier to find your home instance now.
• Search itself has been overhauled. Increase search performance significantly. I also automatically search for related terms as well. You may now see fewer search results, but ideally they should be more relevant. You can also now include basic syntax like:
  • quotes: "some terms that must be together"
  • negative terms: cat -dog (shows posts about cats that don't mention dogs)
  • either or: cat OR dog (shows posts about either cats or dogs). The default search behavior is now an implicit AND, but order doesn't matter.
• I've added several new filters that you can use including:
  • !safeoff -- Disables safe search allowing NSFW posts to appear in the search results (NSFW is now hidden by default)
  • since:YYYY-MM-DD -- shows only posts that have occurred since the specified date
  • until:YYYY-MM-DD -- same as above but in reverse. It will only posts up to the given date.
• I've removed the preferred-instance query parameter from the results URL so it should be easier to share links to search results now.
• The date the post was created or last updated is now displayed in the search results.

Bug Fixes:

• Site performance should now be stable. Fixed a bug related to the database pool that was causing the site to hang.
• Fixed a bug that would cause broken links.
• Fixed various bugs with the crawler causing posts to be missed.

Known Issues:

• If you set your home-instance to a fairly small instance, the number of search results is also relatively small. Once (https://github.com/LemmyNet/lemmy/issues/3259) is resolved. I should be able to show links regardless of what your home instance is set to, allowing you to search the entire Fediverse.
• Currently searching only looks at the post title and body. Comments aren't indexed either. This also is dependent on the above issue on Lemmy itself.

Finally some things to note:

I've started to refactor the code to abstract away Lemmy from the actual search engine. As I now start to prepare to search other Fediverse instances like Kbin, and maybe even Mastodon, etc...