Original report: https://github.com/mattermost/mattermost-server/issues/15012
Some people on the above linked Github issues have reported slow typing on Mattermost.
Also a few people from Mattermost staff have reported the same - see this thread in Ask R&D channel https://community.mattermost.com/core/pl/cgxsqhbxfffn38f8xoqfy38a9c.
Steps to reproduce
1. Start typing a message on Mattermost
2. Wait for text box to catch up with what was typed, sometimes 5+ seconds
Expecting the message box to catch up with my typing with a delay less than 200 ms. The CPU is maxing out whenever I start typing. I can confirm this happens on Chromium as well, and both on Debian and Fedora on different devices.