System Design Notes

A collection of practical system design and distributed systems notes focused on scalability, reliability, and real-world backend engineering.

The goal of this repository is to document:

• system design concepts
• scalability patterns
• infrastructure tradeoffs
• distributed systems fundamentals
• other personal learnings! :)
• and of course LLD/HLD questions

These notes are written primarily for personal reference and interview preperation

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Topics to be covered (Hopefully)

Fundamentals

• Load Balancing
• Caching
• Database Scaling
• Replication vs Sharding
• CAP Theorem
• Consistent Hashing

Scalability

• Rate Limiting
• CDN Architecture
• Queue Systems
• Backpressure Handling
• Autoscaling

Distributed Systems

• Consensus Algorithms
• Leader Election
• Eventual Consistency
• Distributed Locks
• Gossip Protocols

Problems

• Rate Limiter
• Consistent Hashing
• Key-Value Store
• Distributed Unique ID Generator
• URL Shortener
• Web Crawler
• Notification System
• News Feed System
• Chat System
• Search Autocomplete System
• YouTube
• Google Drive
• Video Streaming Platforms
• Ride Sharing Systems

Observability (Future Addition)

• Metrics
• Logging
• Tracing
• Monitoring Pipelines

References

References used across notes may include:

• engineering blogs
• System Design Interview: An Insider’s Guide by Alex Xu