Every four seconds, every active Uber driver sends their GPS coordinates to a server. At peak, that's roughly 5 million updates per minute — before you even count the riders watching their driver move on a map in real time. The location pipeline is the heartbeat of the entire platform. If it slows down, drivers and riders fall out of sync. If it falls over, the app is effectively useless. Building something like this in .NET is a good exercise in knowing when not to reach for a database. Location data is high-frequency, short-lived, and geospatial. A relational database would collapse under the write load. What you need is Redis. This is the first article in a mini-series on designing an Uber-like system in .NET. Here we build the location tracking pipeline. In the next two articles we'll cover the trip state machine and the full system design.…