🏗️ System Design Learning Notes

📂 Topics Covered

File	Description	Status
Learn 01	System Design Basics	✅ Done
Event Driven Architecture	EDA Concepts	✅ Done

🎯 Quick Reference

Key Concepts

Scalability

Vertical Scaling - Add more power (CPU, RAM)
Horizontal Scaling - Add more machines

Load Balancing

Round Robin
Least Connections
IP Hash
Weighted

Caching

Client-side - Browser cache
CDN - Content Delivery Network
Server-side - Redis, Memcached
Database - Query cache

Database

SQL - Structured, ACID compliant
NoSQL - Flexible, eventually consistent
Sharding - Horizontal partitioning
Replication - Master-Slave, Master-Master

Design Patterns

Microservices

┌─────────────┐     ┌─────────────┐
│   API GW    │────▶│  Service A  │
└─────────────┘     └─────────────┘
       │            ┌─────────────┐
       └───────────▶│  Service B  │
                    └─────────────┘

Event-Driven Architecture

Producer ──▶ Message Queue ──▶ Consumer
             (Kafka/RabbitMQ)

Common Estimations

1 Million users = ~100 requests/sec
1 KB per request = 100 KB/sec = 8.6 GB/day
Read:Write ratio typically 100:1

📚 Resources

Last Updated: March 2026