I have intermittently faced each of these issues over the last hour across several European and a US Slack:

* Messages are shown as sent (not grey), then, after several minutes, a "Try to send again" message appears. Or the message turns grey. Or both.

* The webapp randomly reloads. Sometimes already typed messages are preserved, sometimes they disappear. ( I assume a reload happens when a new version is deployed with some "force reload" flag )

* Threads and channels just show a loading spinner forever.

* After switching channels, all fonts disappear and just the menu background remains. No remedy except reload.

Outages happen. They get resolved. That's live, and it's fine.

What is not fine is how ill-equipped the frontend is to deal with such failures.