System Design: URL Shortener

Design a scalable URL shortening service like bit.ly

Requirements

Functional

Shorten long URLs
Redirect to original URL
Custom short URLs
URL expiration

Non-Functional

High availability
Low latency
Scalability
Security

System Components

API Gateway

Rate limiting, authentication, routing

URL Shortening Service

Generate short codes, validate URLs

Database

Store URL mappings, analytics

Cache Layer

Redis for fast URL lookups

Coming Soon

Detailed architecture diagrams, database schema, API design, and scalability considerations.