System Design Interview Fundamentals Rylan Liu Pdf [top] | WORKING ⇒ |

System Design Interview Fundamentals — Detailed Guide

10. Worked Example: Design Photo Sharing Service (concise)

  1. Requirements: upload, view, thumbnails, comments, 100M users, 1M QPS reads, 10k QPS writes, retention 3 years.
  2. API: POST /upload, GET /photo/id, GET /user/id/photos?page.
  3. High-level: client -> CDN (reads) / upload service -> object store (S3) -> metadata DB (sharded), thumbnail generator (async via queue), cache (Redis) for hot objects, search/index service for tags.
  4. Scaling: partition metadata by user-id, use CDN + cache for reads, autoscale upload service, use S3 lifecycle rules for archival.
  5. Consistency: eventual for thumbnails and views; strong for ownership checks.
  6. Monitoring: upload latency, error rates, S3 errors, queue depth.

Part 3: The "Liu" Method for 3 Classic Problems

The PDF usually deconstructs these three "killer" problems. Here is how the fundamentals apply.

Important trade-offs and principles

  • CAP theorem: in presence of network partitions choose consistency or availability.
  • Latency vs consistency vs throughput: e.g., synchronous replication increases durability but hurts latency.
  • Complexity vs correctness: simpler systems are easier to operate.
  • Cost vs performance: caching and replication increase cost.
  • Single source of truth vs eventual consistency: needed for different use cases.

7. Security & Privacy

  • Authentication (OAuth2, JWT), authorization (RBAC, ABAC).
  • Transport security (TLS), encryption at rest, key management.
  • Input validation, SQL injection prevention, secure defaults.
  • Audit logs and least privilege.

Security, privacy, and compliance

  • Authentication: OAuth2, JWT, session tokens.
  • Authorization: RBAC, ABAC principles.
  • Encrypt data in transit (TLS) and at rest.
  • Secret management: vaults, short-lived credentials.
  • Rate-limiting and abuse prevention.
  • Data retention and regulatory compliance (GDPR, CCPA) considerations.

System Design Interview Fundamentals — Rylan Liu (treatise)

Note: below is an original, comprehensive treatise covering the fundamental topics commonly associated with system design interviews (scale, trade-offs, architecture patterns, components, and evaluation). It does not reproduce any specific copyrighted PDF or verbatim text; instead it organizes canonical concepts, examples, and exercises you can use to prepare for system design interviews in the style of many well-regarded guides. System Design Interview Fundamentals Rylan Liu Pdf