common-architecture-diagramming

name	common-architecture-diagramming
description	Standards for creating clear, effective, and formalized software architecture diagrams (C4, UML). (triggers: ARCHITECTURE.md, **/*.mermaid, **/*.drawio, diagram, architecture, c4, system design, mermaid)

Architecture Diagramming Standard

Priority: P1 (Standard)

Guidelines

• Use C4 Model: Context->Container->Component->Code.
• Audience-Centric: Tailor abstraction (Execs vs. Devs).
• Select Type: Sequence (Protocol), ERD (Data), State (Lifecycle), Cloud (Infra). See Selection
• Explicit Labels: Label every arrow (e.g., "Uses", "HTTPS").
• Consistent Notation: Cylinders=DB, Rectangles=Systems, Dashed=Async.
• Metadata: Title, Date, Version, Author.
• Legend Mandatory: Define all shapes/colors/styles.
• Direction: graph LR (Flow) or graph TD (Hierarchy).
• Deployment: Map containers to infrastructure.
• Governance: CRITICAL: Review best-practices.md before starting.

Anti-Patterns

• Mixed Levels: DB columns in System Context.
• Unlabeled Arrows: Ambiguous relations.
• Mystery Shapes: Undefined in Legend.
• Dead Ends: Unconnected nodes.
• Clutter: >20 nodes/diagram.
• Acronyms: Undefined abbreviations.

References

• Diagram Selection
• Cloud Architecture
• C4 Model Guide
• Checklist
• Best Practices