🎯 Goal: Master these concepts to crush any MAANG system design interview

1. Scalability Fundamentals

Vertical vs Horizontal Scaling

• Vertical (Scale Up): Add more power to existing machine (CPU, RAM)
  • Pros: Simple, no code changes needed
  • Cons: Hardware limits, single point of failure
• Horizontal (Scale Out): Add more machines
  • Pros: Nearly unlimited scaling, fault tolerance
  • Cons: Complex, requires distributed system design

Key Scalability Patterns

• Stateless Services: No server-side state, easy to scale
• Database Sharding: Split data across multiple databases
• Microservices: Break monolith into smaller, independent services
• Event-Driven Architecture: Asynchronous communication between services

2. Load Balancing

Load Balancing Algorithms

• Round Robin: Requests distributed sequentially
• Weighted Round Robin: Different weights for different servers
• Least Connections: Route to server with fewest active connections
• IP Hash: Route based on client IP hash
• Geographic: Route based on client location

Types of Load Balancers