Note that this page is separate from a landing page (like the front page or a category) and a product page. Those have very strict requirements for how long a page component can take to render. This one is allowed to break the rules.

I wonder what they've got backing these pages. DynamoDB? memcached in front of S3? Redshift or AWS Lambda?

Interesting that what are essentially tabs or buttons are implemented as full server round trips. Seems like Amazon generally prefers that methodology over client side tab switching. Not sure why, when they could probably load what is essentially static information and just show/hide the containing elements.