URL Shortener Service

A real backend: REST API, base62 IDs, click analytics, and caching.

Build plan

1. 1
   POST /shorten — store long URL, return short code
2. 2
   GET /:code — 302 redirect, increment click counter
3. 3
   Add a Redis cache for the most-hit codes
4. 4
   Build a tiny dashboard with click counts over time