What framework do you follow in a 45-minute system design interview?

Answer

1. Clarify requirements: functional (core features only) and non-functional (scale, latency, availability, consistency). ~5 min.
2. Estimate: users, QPS, storage, read/write ratio.
3. Define the API and the data model.
4. High-level design: clients, load balancer, services, database, cache, queues, storage.
5. Deep dive into 1-2 components the interviewer cares about (bottlenecks, scaling, partitioning).
6. Trade-offs, failure modes, monitoring, and what you would improve with more time.

• Think aloud, draw boxes, state assumptions, check in with the interviewer.

Key terms

• QPS
• Load balancer
• Cache
• API