Staff+ Interview Prep (v15)

40 system design cards for Staff+ interview prep.

v15 pre-rendered HTML (recommended on Pages) · Full interactive v15 · Static HTML (no JS)

Delivery framework

1. Requirements (3–5 min) — functional + NFRs, draw out-of-scope line
2. Estimation — QPS, storage, bandwidth to justify decisions
3. API design — REST / WebSocket / gRPC, name routes explicitly
4. Data model — entities, SQL vs NoSQL with justification
5. High-level design — client → LB → services → DB/cache
6. Deep dives — 2–3 hardest problems, tradeoffs, failure modes

Architecture framework

Universal skeleton → two questions (read vs write · money vs likes) → five archetypes: read-heavy feed, transactional core, real-time pipe, marketplace, compute pipeline. Open full section · Source article

Key numbers: Redis ~100K–1M ops/s · Single DB ~10K–50K QPS · Kafka ~1M+ msgs/s · Cross-region ~100–200ms