Design a URL Shortening Service
Company: Microsoft
Role: Software Engineer
Category: System Design
Difficulty: medium
Interview Round: Onsite
Design a production-ready URL shortening service.
The system should:
- Accept a long URL and return a short, unique alias.
- Redirect a short URL to the original long URL with low latency.
- Scale to high read traffic.
- Handle code generation safely and explain how collisions are prevented or resolved.
- Discuss storage, caching, APIs, and follow-up concerns such as expiration, analytics, and abuse prevention.
Explain your architecture and the trade-offs in your design.
Quick Answer: This question evaluates expertise in designing scalable, low-latency web services, covering URL alias generation and collision handling, storage and caching strategies, API design, and operational concerns like expiration, analytics, and abuse prevention.