[webjames]

With the shopping cart example, I'm not sure I understand how session identity can be preserved if I clear my local storage/cookies?

[zackbloom]

It's moving that shopping cart data from being stored at a single origin, to being stored in the network all around the world. The advantage of that in that use-case is you can render your site just as quickly as if it was a static website, but it can contain the customer's personal shopping cart data.

[adrianmonk]

The shopping cart is still stored somewhere, but when the user has cleared their cookies, etc., what information do you have that will let you it's their shopping cart so you can find it again?

There's a (K,V) pair somewhere, but in order to get V, you need K, which you've lost.

[BHSPitMonkey]

If the user signs in, move their shopping cart data from a key derived from their session ID to a key derived from their account ID. When a user is signed in, data is read from the latter.

[ericcholis]

You'd still need some identifier, ie: a cookie, to link the KV store and your session.