HOW UBER COMPUTES ETA AT HALF A MILLION REQUESTS PER SECOND

Summary from the TLDR Web Dev newsletter

Every Uber ride requires around 1000 ETA requests - more than 18 million Uber rides are completed daily. Accurate ETA calculations are essential to their business function, yet this is a surprisingly complex problem to solve. This article explains how routing algorithms, traffic information, and map matching are used by Uber engineering teams to correctly project ETA for their customers.