It's pretty darned tough. Like others have said, it takes a lot of work, including the dreaded global timeline. It's unfortunate, because this is really limiting #nostr's reach.

There are a lot of technical features that could make it much easier, but they're not the sexy features that devs want to work on, such as:

- Limit timeline to languages you can read

- Filter out certain words from global timeline (either temporarially or eternally)

Honestly, just these things would alllow filtering out so much uninteresting/spam/garbage, and might make the global timeline tolerable.

If anyone knows of any clients that have these features, please do let me know!