System Design Interview: A Practical Framework That Works
Learn the RESHADED framework — Requirements, Estimation, Storage, High-level design, APIs, Deep dives, Edge cases, Deployment — used by candidates at FAANG companies. Step 1: Clarify requirements (5–8 minutes). System design interviews test whether you can translate ambiguous product requirements into a scalable architecture. Interviewers care less about memorized buzzwords and more about structured thinking, trade-off analysis, and clear communication. Step 2: Back-of-envelope estimation. Calculate QPS (queries per second), storage per day, and bandwidth. Round aggressively — interviewers want order-of-magnitude reasoning, not precision. Step 3: High-level design. Draw clients → load balancer → app servers → cache → database. Add CDN for static assets, message queue for async work, and search index if needed. Name each component and explain why it exists. Step 4: Deep dives interviewers love. Common mistakes to avoid.