Ride matching. Taxis in two regions

A taxi service in Europe and the USA: driver locations bypass the database, each region has its own stream (geo-partitioning), and on New Year’s Eve Europe is split into cells.

Diagram of ride matching: car locations flow into fast in-memory streams per region, bypassing the database, and riders are paired within a map cell.

System Design — Load balancers, caches, queues and regions: build a system that holds the load