The recording will be available later, but if you're interested in enabling a global consistent view on hashtags, know stuff about DHTs or #ActivityPub relays, you can have a look at the paper: https://git.orlives.de/schmittlauch/paper_hashtag_federation/src/branch/master/paper_hashtag_federation.pdf
Please contact me about any questions, remarks or other feedback!
So here's a TL;DR:
The problem about the current state of hashtags in the fediverse is that users have a fragmented view on posts, depending on their instance. Some posts containing a hashtag never reach your own instance, so you won't see it. This is bad for decentralisation and coordination.
I plan to throw some additional P2P stuff at the fediverse: All instances are distributing the responsibility for relaying or storing posts (just their IDs) among themselves using a Distributed Hash Table. ->
Btw, he slides of my #ActivityPubConf talk are available here: https://git.orlives.de/schmittlauch/paper_hashtag_federation/src/branch/master/talk-slides.pdf
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