Behind every food-delivery app's "your courier has been assigned" notification sits a small optimization problem, run over and over in real time: given a pool of idle couriers and a queue of freshly placed orders, which courier should pick up which order to keep total delivery time low? This simulator renders a live 3D city with fixed restaurants, a fleet of couriers, and a steady stream of spawning orders, and runs a real greedy minimum-cost bipartite matcher — scoring every courier against every waiting order by pickup-plus-dropoff distance and assigning the cheapest pairs first — with an optional order-batching rule that lets one courier carry two same-restaurant orders when their drop points are close enough. Tune the order rate, fleet size, and batching radius and watch average delivery time, courier utilization, and courier-km per order respond live.