Design patterns·The shape of the whole application
every request in the application arrives at one handler first, and that is where authentication and routing live.
Front controller
Also calledfront controller pattern, single entry point, dispatcher
A single entry point that receives all requests and dispatches them, so cross-cutting concerns are handled once rather than per page. Every modern web framework's router and middleware pipeline is this pattern, which is why almost nobody implements it deliberately any more. It is worth naming because it explains where framework-level behaviour comes from when nothing in your handler mentions it.