I don't like releasing large chunks of software at once, but there are situations where it's easier to swap out a large piece of interdependent pieces than it is to replace them piecemeal.
Except you have to make it through the release.
I worked on replacing the Family Tree database on familysearch.org with a new one. Old was Oracle, new was Cassandra.
It started at 12:30am and extended, with various emergencies that were handled more or less gracefully by amazing people, until 6:21am. And then it was done, and we had to start keeping it up.
After a few surprises that none of our simulations exposed, I have enough rest again and can function more or less normally.
However, the anxiety I felt during the release and the uncertainty I felt in the days just afterwards all added up to a feeling I don't remember feeling before.
Then I realized that the flashbacks and the irrational worry about keeping things working - probably some mild form of post-traumatic stress.
Certainly only a taste of what others go through who were in danger of losing their life and barely survived. Not trying to imply that my experience is anywhere near that sort of thing.
I'm just trying to process my emotions and am hopeful this helps someone know they're not alone.