Pattern Proposal: Layered Service-Engine Orchestration

Summary

Separate user-facing or workflow service orchestration from internal evaluation and execution engines.

Candidate Pattern

• ID: layered-service-engine-orchestration
• Classification: architectural
• Maturity: strategic_direction
• Type: emerging

Observed Signals

No specific signals listed.

Evidence

Supporting Evidence

• src/cas_runner/governance/governance_action_service.py (GovernanceActionService) - Encapsulates application workflow for governance actions.
• src/cas_runner/governance/governance_action_engine.py (GovernanceActionEngine) - Provides lower-level execution mechanics for discrete governance actions.
• src/cas_runner/governance/compliance_engine.py (ComplianceEngine) - Evaluates compliance rules independently of orchestration.

Scope Assessment

• Evidence Strength: high
• Confidence: high
• Applies to: ideas-to-life-cas

Rationale

• Intent: Prevent business logic and file system coordination from entangling with granular compliance or action evaluation rules.
• Context: The governance module must coordinate multiple concerns: compliance verification, action calculation, and disk persistence.
• Force: Coupling verification logic with execution makes individual parts difficult to unit test
• Force: High-level callers (CLI, Runner) need a single cohesive facade to perform governance actions

Traceability

Artifact source: proposed-patterns