There is a book "The People's Republic of Walmart: How the World's Biggest Corporations are Laying the Foundation for Socialism" describing how e.g. Walmart (there is also Amazon now) does its own large-scale planning.

It's kinda funny that the "socialist calculation debate" has largely settled on "okay, it's probably possible but requires way too much of computational resources and accurate data gathering" — and now we spend insane amount of resources on AI data centers and tracking/surveillance on literally everything. And, of course, all of those resources won't end up being used for solving (or even accurately figuring out) the actual economical problems we face today.