Behavior

Behavior Documentation

This section documents runtime behavior — how components interact over time to accomplish tasks.

Why Sequence Diagrams?

Sequence diagrams are ideal for illustrating:

  • Multi-step workflows across services or components
  • Request/response patterns including error handling
  • Async operations with callbacks, retries, or timeouts
  • Side effects and their ordering

When to Create One

Rule of thumb: If a flow involves 3+ actors or has non-obvious error handling, document it with a sequence diagram.

Common scenarios:

  • User authentication flows
  • Data synchronization between systems
  • Event-driven workflows
  • API call chains with fallbacks

Format

We store diagrams as Mermaid or PlantUML source code:

FormatProsBest For
MermaidNative Hugo rendering, simpler syntaxQuick diagrams, basic flows
PlantUMLMore features, styling optionsComplex diagrams, formal docs

Templates

See the Sequence Diagram Template for examples and best practices.