📝Key Takeaways
- 1Tier 1 (Beginner): URL shortener, paste bin, rate limiter — focus on fundamental concepts
- 2Tier 2 (Intermediate): Chat system, news feed, notification system — multi-component designs
- 3Tier 3 (Advanced): Distributed KV store, Google Docs, Uber — deep distributed systems knowledge
- 4Tier 4 (Staff+): Design Kafka, design a CRDT system, design ML feature store — novel system design
Practice Questions by Difficulty
The best way to prepare for system design interviews is to practice with a wide range of questions at increasing difficulty. For each question, time yourself (45 minutes), use the RESHADED framework, and self-evaluate using the rubric below.
Question Tiers
1. Design a URL Shortener (TinyURL) — hashing, KV store, redirection
2. Design a Paste Bin — text storage, expiration, share links
3. Design a Rate Limiter — token bucket, sliding window, distributed state
4. Design a Key-Value Store — in-memory with persistence, replication
5. Design a Task Queue — producer-consumer, retry, dead letter queue
Focus: core concepts, single-service design, basic data flow
✅Self-Evaluation Rubric
After each practice: (1) Did I clarify requirements before designing? (2) Did I estimate scale? (3) Did I draw a clear high-level architecture? (4) Did I explain trade-offs for every decision? (5) Did I go deep on 2-3 critical components? (6) Did I identify and address bottlenecks? Score 1-5 on each. Aim for 4+ on all six.
Advantages
- •Tiered questions build skills progressively
- •Self-evaluation rubric provides objective feedback
- •Practicing with time pressure simulates real interviews
Disadvantages
- •Self-practice lacks interviewer feedback
- •Questions alone don't teach — study the underlying concepts first
- •Over-practicing specific questions creates false confidence
🧪 Test Your Understanding
Knowledge Check1/1
What should you always do before starting to design in an interview?