In many ways, #deltachat deals with typical peer to peer challenges. The message transport is treated as dumb, so it can not host group membership metadata or key directories like #WhatsApp, @signalapp and #telegram do. Our dumb-server protocol philosophy is also very unlike #matrix which has very stateful servers with lots of relational metadata and required synchronization state. So #p2p networking like recently introduced for #webxdc realtime channels flows rather naturally for us ....