The product detail page, the category listing, the recommendations slot and the store colleague's lookup all wait for multiple backend systems to answer before they can render. The page makes five calls, waits for the slowest, and dies when one of them does.
It takes eight seconds for a store colleague to look up whether a product is in stock across locations, so they say they do not have it. The account page waits for orders, entitlements, loyalty, preferences and contracts before it loads, and the customer sees six seconds of spinner. Swedish shoppers click a Danish search result, land on a page priced in Danish kroner, and leave.