The Infrastructure Nobody Sees: Why DNS, CDNs, Load Balancers and APIs Keep the Internet Running

Until it breaks. In 2021, a DNS-related issue at Akamai took down a wide swath of the internet at once. CNBC reported that the outage left Delta Air Lines, Capital One, GoDaddy, Vanguard, UPS, and Costco all loading slowly or showing DNS failures, and Delta customers specifically couldn't check into flights through the airline's own app. None of those companies had a problem with their own code. The address book that routes traffic to them simply stopped working for a while.