Amazon’s fulfillment center in Opa-locka is aptly named: It fulfills the impossible-seeming task of having almost any item imaginable shipped directly to one’s door in a matter of hours.

A few clicks of a mouse set into motion a veritable ballet of autonomous functions and approximately 2,000 human packers in Northeast Miami-Dade that allows a shopper, or his intended recipient, to pick up packages from their doorsteps.

But how does Amazon — and other e-commerce shippers including Target and Walmart — really work to deliver more than an estimated $135 billion in e-commerce sales this holiday season, up from $119 billion last year?

Read more from our news partner The Miami Herald.