System Design - Series Overview

Architecture conversations kept surfacing the same decisions: how consistent does this need to be, where does it shard, what gets cached and at what level. I started keeping notes on the reasoning rather than the answers - the trade-offs that drive the design, not the design itself. Chapter 1 covers the vocabulary everything else in the series links back to: scalability, CAP theorem, consistency models, caching, sharding, and a 7-step framework for working through a design problem. Each subsequent chapter applies that vocabulary to a specific system: stated requirements, explicit trade-offs, and a final design. ...

November 5, 2025 路 2 min 路 366 words

System Design - Fundamentals

This is Chapter 1 of the System Design series. Architecture reviews and design discussions keep coming back to the same vocabulary regardless of what鈥檚 being built. I keep this list so I鈥檓 reasoning from consistent definitions each time, not re-deriving the same trade-offs from scratch. Core concepts Systems Always Lose Consistency - CAP Is Fundamental Scalability Availability Latency Consistency CAP Idempotency Fault tolerance 1. Scalability Vertical scaling (bigger machine) buys time but hits a ceiling fast and creates a single point of failure. Horizontal scaling (more machines) is the default for anything expected to grow past a single box, at the cost of needing to handle state, coordination, and partial failure across nodes. 2. Availability Usually expressed in nines: ...

November 19, 2025 路 8 min 路 1590 words