Sheet 17

Final Executive Summary Cheatsheet

Dense, high-yield one-page whiteboard reference sheet for FAANG system design interviews.

The 60-Second Whiteboard Talk-Track (Auto-Interpolated Live)

"10M MAU → 2.0M DAU → 400k concurrent → ~3,333 raw RPS → ~6,667 Peak RPS with a 2x safety buffer. CDN absorbs 98% of traffic. Gateway: 9 pods across 3 AZs with 3.5ms overhead. Backend: 29 pods across 5 microservices plus gateway. Kafka: 3 brokers, 6 partitions, ~6.51 MB/s producer throughput. Postgres: 231 GB disk, ~4,800 QPS after a 95% cache hit rate, plus 4 read replicas. Redis: 3 shards, 9 GB RAM. DLQ with 4-tier exponential backoff. Multi-AZ end-to-end. Total monthly infra: ~$16,472 ($8.24 per 1k DAU)."

✓ Say this exact chain first in your interview to establish instant credibility before sketching architecture boxes.

Headline Architectural Numbers (Normal Scenario)

Users

Edge & CDN

Gateway

Backend Fleet

Latency

Kafka Bus

Database

Cache

Economics