Many of the Stack Exchange sites have been going off and on such as Worldbuilding, Medical Sciences, Psychology & Neuroscience and Writing over the last couple of hours for me. The maintenance page shows, referring to the Twitter account and Status blogs.
Neither the Twitter account nor the Status blog show any indication of a current update.
Fortunately however, meta is fine ATM... Could we have an update as soon as convenient?
2 hours after posting, the sites are up, but slow to load. (Southern UK).
5 hours after posting, all sites are going up and down including meta.
Tweet by SO an hour before this edit:
We’re aware something is happening, and we’re working on it. We’ve tried unplugging and plugging back in, but that didn’t fix it.
16 hours after the post a (hopefully) final Tweet:
I think we discovered what was wrong. Things should be back up!