Wanted to write about this for some time now, finally published about how we designed our signup flow for Nextcloud considering it is open source and decentralized.
I think there’s a bunch of good learnings in there which other decentralized projects could pick up, especially since some of them already do something similar but not quite the same. 
Also a Tweet and Mastodon post if you want to share & like
- Twitter https://twitter.com/jancborchardt/status/1305472266126405632
- Mastodon https://mastodon.social/@jancborchardt/104863134957714055
Also cc @bumbleblue since I remember we talked about this some time ago, possibly at CCC? Might be an interesting design pattern for the https://decentpatterns.xyz design patterns library?