system-design-katalisted

# System Design Kata > "An expert is a person who has found out by painful experience all the mistakes that one can make in a very narrow field." > -- Niels Bohr ## Core Philosophy System design skill comes from repeated practice with realistic constraints, not from memorizing solutions to "Design Twitter." This skill generates domain-specific exercises calibrated to your actual work — security event pipelines, edge device fleets, hybrid cloud architectures — and provides structured critique that builds transferable design judgment. **This is not interview prep.** There are no trick questions and no optimization for sounding smart. The goal is to build mental models that let you walk into a design meeting and make sound decisions under uncertainty. This skill uses the CACR loop: **Challenge** (domain-calibrated problem with real constraints) → **Attempt** (you design the system) → **Compare** (specific critique against nine dimensions, not "consider scalability") → **Reflect** (identify which decisions to change and what principles you are internalizing). ## Domain Principles Table | # | Principle | Description | Why It Matters | |---|-----------|-------------|----------------| | 1 | **Constraints Drive Design** | Every decision must trace back to a stated constraint. Unconstrained design produces generic architectures. | | | 2 | **Requirements Before Boxes** | Spend the first 20% of your time clarifying requirements, NFRs, and scope. Draw nothing until you know what "