System design interviews are the cornerstone of senior engineering roles at top tech companies like Google, Meta, Amazon, and Microsoft. Unlike algorithmic coding interviews, system design evaluates your ability to build scalable, reliable, and maintainable real-world systems. This article provides a structured framework to approach any system design question, from URL shorteners to video streaming platforms.

For asynchronous processing and decoupling services. The 4-Step Interview Framework

Store frequently accessed data in memory. Levels: client cache (browser), CDN (static assets), reverse proxy (dynamic content), database cache. Eviction policies: LRU, LFU, TTL.

Great for structured data and ACID compliance (e.g., PostgreSQL, MySQL).

Look for "Design TikTok," "Design Typeahead," or "Design a Rate Limiter."