[kiliankoe]

But it's chromium serving local content. That is somewhat of a difference.

I run Slack only in Safari. It works significantly better than the desktop app.

[Piskvorrr]

I don't think serving local content would explain why the desktop app insists on munching through all the available RAM (on a single team, no less!), something else must be going on. But that's actually a pretty good suggestion - I'll try the web version, thanks.