How DNS Actually Works: Resolution Hierarchy, Caching, and Production Failure Modes (opens in new tab)

DNS Is an Indirection Layer, Not a Lookup Table The "phonebook" metaphor everyone reaches for is actively misleading — and worse, it frames DNS as solved infrastructure when it's anything but. A phonebook is a static mapping. You look up a name, you get a number, done. DNS is something fundamentally different: a decoupling mechanism that separates stable human-readable identifiers from the volatile, ephemeral IP addresses underneath them. That distinction has enormous architectural consequenc...