System Design 面試流程

Clarify → Design → Validation

Clarify

• Scenarios Requirements
  • Functional Requirements
  • Non-Functional Requirements

Functional Requirements

• 使用者是誰: Real Users / Internal Developers / Internal Services
• User如何和系統互動: UI / API / IoT
• 系統要提供什麼功能
• Read/Write Patttern: Read-Heavy / Write-Heavy

Non-Functional Requirements

• Availability/Reliability
  • SLO(Service Level Objective)
  • Database Replication
  • Blob Storage, PubSub
  • Retry
• Scalability
• Consistency: 如果有很多DB會有數據不一致問題
• Latency: 99 percentile: 99%的request在多少時間內完成
  • Read Optimization: Cache, CDN, PubSub
  • Write Optimization
• Security,Privacy and Compliance
• Real Time vs Async
• Observability
  • Logging, Monitoring, Alerting
• Disaster Recovery

Design

資料怎麼傳輸怎麼儲存

Overall Diagram

• API Design
• DB Design

Users/application/services → API Gateway → Servers → Database

DB Design

• Query Patterns / Data Model
• SQL vs NoSQL
  • NoSQL: Blob Storage, Cache, Column Store, Document Store, Graph DB
• Kafka
• Replication and Sharding

Validation

• Go Over the Requirements