Opening a conversation via a notification is slow

[duogenesis]

When you open a conversation via a notification, connecting to the chat server and refreshing the conversation takes an annoyingly long time. The problem is probably worse for users with big inboxes.

One (part of a solution) might involve more aggressive caching on the client. Though I'd rather use this as a last resort because I don't want to add much complexity to the frontend.

Another solution might be to move away from XMPP. When logging-in via XMPP, a connection needs to be established before subsequent activities happen. This takes a few round trips between the server and client. But it's possible to fetch a conversation in just one round trip by offering the authentication token when requesting the conversation. XMPP doesn't allow this, but a custom protocol can.

Related: duolicious/duolicious-backend#446