System Design (2–5 yrs): 12 core problems + what interviewers actually score

What interviewers score (2–5 yrs)

• Requirements: asks the right questions, clarifies constraints
• Tradeoffs: makes choices with reasoning (not just diagrams)
• Data model: keys, indexes, consistency
• APIs: clear request/response, pagination, idempotency
• Reliability: failure modes, retries, queues, rate limits
• Scale: bottlenecks, caching, sharding basics

12 core problems to practice

1. URL shortener
2. Rate limiter
3. News feed / timeline
4. Chat (1:1 + group)
5. File storage + sharing links
6. Search autocomplete
7. Notification system
8. Metrics/analytics pipeline
9. Job board (filters + ranking)
10. Payment ledger basics
11. Feature flags
12. Logging + alerting basics

2‑week prep plan

• Week 1: 6 problems (1/day) with a written rubric
• Week 2: 4 problems + 2 full mocks

Apply now (StackCV links)

• SDE‑2 / SSE openings
• Senior/Staff openings