Dependency and Boundary Decision Examples

Positive example — volatile integration boundary

• Context: stable policy uses a provider with independently changing failure semantics.
• Mode: domain-centric.
• Decision: define a consumer-owned port in policy terms and adapt the provider at composition time.
• Why it fits: volatility and translation justify the boundary.

Negative example — interface per implementation

• Context: one stable internal implementation has no alternate consumer, lifecycle, or test need.
• Mode: framework-native.
• Bad decision: add forwarding interfaces and wrappers only to claim dependency inversion.
• Better decision: use the implementation directly and introduce a boundary when evidence appears.