Walmart.com is also using React, and Walmart labs developed significant tooling for server-side render and partial render caching for specific components. They've published a lot of articles on their technology choices and how well they do.

Amazon's above the fold render does appear a little faster, but their total payload and load time is much larger/slower.

The site is ok, but loading images takes forever.

Agreed. The top-end images on the homepage is way too heavy. The e-commerce subpages are slightly better image-wise: https://jet.com/c/fashion/men/shoes/5209961250?experienceId=...

The main problem is most of the images are extra large and poorly optimized (they are all preloaded it seems, as Next.js does automatically). Even on my fast fiber connection it flashes.

For example, this product image is 63kb:

https://jetimages.jetcdn.net/md5/f442c4124ca2fb7537503a592a7...

But on the page it’s only loaded 360x360 px but are downloaded at 700px.

And F#

Nice, the site looks great. Good job jet.com devs, sounds like a fun project.