Basics

Build the backend of a live bus-tracking app, one piece at a time.

Buses send their position every few seconds, and riders ask where their bus is. You start with one server answering one request. By the last lesson your system handles more than a thousand requests a second, with a database, a cache, a queue, a load balancer and an API gateway, and you know why each one is there.

No experience needed. Every new word is explained where it appears.