As much as I shit on the Twitter takeover, I actually haven't experienced any service degradation (nor was I really expecting to; they're excellent engineers despite what Elon Musk might say).
The only service degradation I've ever experienced were long-running issues that existed before the takeover. Specifically, the two most common issues I'd notice were:
-
"psych!" notifications
The notifications tab would briefly display a number to indicate new notifications but then the number would disappear, I'd click over to the tab to see if there were new notifications or not and there were none. Then after some delay (~10-20 seconds) the number would reappear along with the matching notifications.
I assume that this was due to some sort of eventually consistent architecture on their end, but it would have been a better UX if they would not tease me with the initial brief notification that disappeared and just wait until the notifications were actually ready.
-
Completely missing replies
If one of my tweets or threads blew up there would sometimes be replies that would just not show up at all in my notifications tab (neither the "All" nor the "Mentions" tab). I even made sure to disable notification filtering and they were still definitely missing. The way I would find out is by manually browsing the replies to the thread and seeing people who were definitely trying to reply to me (i.e. they had not unsubscribed me from the reply).
I assume that this was some sort of load shedding on Twitter's part on high traffic discussions.