I jumped straight into the product side (who uses it, what are the core flows) and kind of forgot to anchor on scale for way too long.
Start by clarifying requirements and constraints, then outline a high-level design covering key components like URL encoding, storage, and redirection. Discuss trade-offs and potential optimizations, and tie back to product goals and user experience.
Pro tip: Emphasize scalability and reliability from the start, and propose metrics to measure success, such as latency and uptime, to show product thinking.
Ask questions to understand scope: expected traffic, read/write ratio, custom aliases, expiration, analytics, and security needs.
Outline core components: a web server for API, a database for mappings, and a redirection service. Describe the flow from shortening to redirecting.
Discuss URL encoding (e.g., base62), hash function, collision handling, and storage choices (SQL vs NoSQL). Consider caching for hot URLs.
Address how to scale (e.g., sharding, replication), ensure low latency, and handle failures. Mention load balancing and CDN for redirects.
Talk about user experience, analytics, abuse prevention, and potential monetization. Suggest metrics to evaluate success.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.