System Design — Free Back-of-the-Envelope Calculator & Interview Rubric

CONFIGURATION

TRAFFIC & EDGE

User Metrics Frontend & CDN API Gateway Load Balancer

COMPUTE & DATA

Backend Services Network Latency Kafka Event Bus Database (PG)Cache (Redis)

RESILIENCY & OPS

DLQ & Errors Traffic Spikes & DDoS Observability

CLOUD & COST

Cloud Mapping Infra Picker Cost Estimator

REVIEW & PRACTICE

Summary Cheatsheet Interview Practice Live Architecture Rubric & Checklist Reference Library 30 Core Concepts

Pure JS Engine● Live

Peak RPS6,667

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App Pods29

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DB QPS4,800

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Cost/mo$16,472

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