I think the most reasonable guess is that they have some backend system that continously pushes some status json/xml file to an S3 bucket.

Then there's the frontend, that apparently periodically reads this file from S3 and caches the results.

I guess the comment they added on the top after two hours of being in the dark was likely manually added to the web frontend.

Obviously all of this would be hilariously badly designed if it was made this way. Still...