Better search functionality
The current state of postActiv's search system is pretty sad. It's very slow and it doesn't contain options for faceted search.
We could have plugins that implement an external backend like Solr or Sphinx, but I also think there could be something done with the core search functionality as well.
(Relevant discussion: https://gs.archae.me/notice/264469)
Desirable but not really a huge priority until the bitrot is dealt with.
For the record, the Sphinx search is what was historically used on Identi.ca prior to the pumpio split.
Do you have a ballpark figure on the amount of users and notices that could end up in the search index?
Some instances have several million notices if that's an indication. Typically most have notices in the hundred thousands, which is enough for the existing search to slow to a crawl.
I'm still thinking we could optimize the core search functionality too since a simple SELECT query on the database is much faster than via the web.