a URL shortener, one machine

The brief

Design a link shortener that runs on one machine and keeps every promise made during requirements clarification: generated names, fixed destinations, public redirects, recorded requests, and mappings that last at least five years.

This is the first full design walkthrough in the course. It is deliberately small. The goal is to see every piece of the method once, end to end, before the same method is applied to systems that need many machines.