系统设计问题(在面试中或实际工作中)受益于一个结构化的方法——阐明需求、估计规模、从高级设计到详细设计,以及讨论权衡。方法化的方法会导致更好的设计。
结构化的方法
1. CLARIFY REQUIREMENTS → functional (what it does) + non-functional (scale, latency,
availability, consistency); scope it (don't assume — ask questions, narrow the problem)
2. ESTIMATE SCALE → users, requests/sec, data volume, read/write ratio → informs the design
3. HIGH-LEVEL DESIGN → main components and data flow (clients, services, databases, caches,
load balancers, queues); draw the architecture
4. DETAILED DESIGN → data model/schema; key components in depth; APIs; specific challenges
5. SCALE & OPTIMIZE → identify bottlenecks; apply techniques (caching, load balancing,
sharding, replication, async); discuss TRADE-OFFS
6. ADDRESS concerns → reliability, consistency, edge cases, failures
