System Design Jargon

To Do

1. What is System Design?
   • What problems it solves
   • High-level vs Low-level design
   • Real examples (Instagram, WhatsApp)
2. Scalability Basics
   • Vertical vs Horizontal Scaling
   • Stateless vs Stateful servers
   • Load vs Traffic vs Users
3. Performance Concepts
   • Latency vs Throughput
   • QPS (Queries per second)
   • Bottlenecks
4. CAP Theorem
   • Consistency
   • Availability
   • Partition tolerance
   • Real DB examples (Mongo, Postgres)
5. Load Balancers
   • Why load balancers exist
   • L4 vs L7
   • Round-robin, least connections
   • Where Nginx / Cloudflare fit
6. Databases
   • SQL vs NoSQL (when & why)
   • Indexing (B-tree, hash — concept level)
   • Transactions & ACID
   • Replication vs Sharding
   • Read replicas
   • Schema design basics
   • Hot partitions problem
7. Caching
   • Why caching exists
   • Cache-aside pattern
   • Read-through / Write-through
   • Cache invalidation strategies
   • Redis vs CDN
   • TTL
8. Messaging & Async Processing
   • Why async systems exist
   • Message queues
   • Kafka vs RabbitMQ (high level)
   • Background jobs
9. API Design
   • REST vs GraphQL
   • Pagination
   • Versioning
   • Rate limiting
10. Designing Real Systems Order to Follow
    1. Requirements
       1. Functional Requirements
       2. Non Functional Requirements
    2. Identify Core Entity
    3. API Designing
    4. High-level diagram
    5. Low-level diagram
    6. Data flow
    7. Bottlenecks
    8. Improvements
11. Advanced & Real-World Concepts
    • Rate limiting algorithms
    • Circuit breakers
    • Service discovery
    • CDN
    • Observability (logs, metrics, tracing)
    • Failover & disaster recovery

Questions

1. URL Shortener
2. Authentication System