Amazon are bad at consumer software, with the exception perhaps of the kindle. Emphasis on consumer, because they have fantastic enterprise/cloud engineers.

They have, frankly, some of the worst UI/UX design of any company in the same spaces that they exist in. Look at even their store listings, it’s a complete mess of information sprawled over the pages.

They do not optimize for performance or have a culture of squashing UI bugs unless it’s measurably stopping conversion for them.

Hell there’s even been times I’ve reported html issues to their teams and been asked to provide the CSS fixes to them to integrate in.