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Intro2026-05-19

Devlog: High-Level Design & System Design​

Starting to work through high-level design (HLD) — the practice of designing large-scale distributed systems. Unlike LLD which focuses on class relationships and design patterns, HLD is about how systems are structured at a macro level: services, databases, caches, queues, and the tradeoffs between them.

The main resource I'm using is the System Design book by Alex Lu, which I'm working through chapter by chapter. Notes are a mix of scanned pages and my own commentary.

Key topics covered in HLD include:

  • Scalability: Horizontal vs. vertical scaling, load balancing, and stateless services.
  • Storage: SQL vs. NoSQL tradeoffs, replication, sharding, and indexing.
  • Reliability: Fault tolerance, redundancy, and designing for failure.
  • Performance: Caching strategies, CDNs, and reducing latency.
  • Communication: REST, message queues, and event-driven architectures.

Sources and Credit​

These notes are heavily informed by:

  • System Design by Alex Lu

I work through the material chapter by chapter, scanning my handwritten notes and supplementing with my own understanding.