Nothing about the screens changed between the first order and the twenty-thousandth a minute. Everything behind the arrows did. The skill is knowing which problem arrives at which scale, and not building the festival-night version for the first family.
Numbers on this page are rounded, illustrative estimates for explaining the ideas. They are not any company's real figures. The screens are screenshots from a quick-commerce app, plus two drawn stand-ins for the order placed and delivered screens. AWS icons are the unmodified official set.