Non-happy paths are where platforms earn trust.

Every exception has a state transition, a visible status, an audit record, and a retry/escalation path.

Examples you should handle explicitly

Order blocked; breaches recorded and shown.

Order status reflects remaining quantity.

State updated; operator guidance displayed.

Reconciliation marker + escalation workflow.

Failure reason + retry path + alert.

Surface staleness and block risky actions.

Operators must reconstruct context quickly during incidents.

Cross-links across the public site for architecture, trust, specialty modules, and rollout.

Lifecycle states for portfolio, compliance, orders, and settlement.

Structured logs, trace context, and queue visibility.

Immutable evidence model for critical workflow actions.

Public service communication and health snapshot.

Port-based adapters for external providers and systems.

Rule checks, severity, and governed override patterns.