11  Operations & Maintenance

11.1 Testing Strategy

Testing must validate both functional correctness and transition safety in a coexistence architecture.

11.1.1 Functional Testing

  • Verify command APIs enforce business rules and return consistent error models.
  • Validate event publication for relevant domain changes.
  • Confirm consumer query behavior returns correct data shapes and authorization outcomes.

11.1.2 Integration and Contract Testing

  • Contract tests for event envelopes and API schemas.
  • Backward-compatibility tests for versioned contracts.
  • End-to-end flow tests covering write -> event -> query -> consumer update.

11.1.3 Performance and Resilience Testing

  • Load tests for peak event throughput and query concurrency.
  • Soak tests to identify memory, connection, or retry degradation over time.
  • Failure-injection tests for transient downstream outages and retry behavior.

11.1.4 Regression and Release Validation

  • Automated regression suites executed for each release candidate.
  • Release gates tied to critical scenario pass rates and non-functional thresholds.
  • Post-deployment verification checklist for production readiness.

11.2 Monitoring, Alerting, and SLOs

11.2.1 Telemetry Model

Capture telemetry for:

  • API latency, error rate, throughput, and saturation indicators.
  • Event publication success rate and consumer lag.
  • Data reconciliation status and drift counts.
  • Security events and authorization failures.

11.2.2 Suggested SLO Categories

  • Availability SLO for command and query endpoints.
  • Latency SLO for core API operations.
  • Freshness SLO for event-to-consumer synchronization.
  • Reliability SLO for successful event processing and retries.

11.2.3 Operational Dashboards and Alerts

  • Role-specific dashboards for support, engineering, and platform teams.
  • Actionable alerts mapped to runbook procedures.
  • Correlation-aware tracing to accelerate incident triage.

11.3 Incident and Problem Management

  • Standard severity model and escalation pathway for integration incidents.
  • Runbooks for common failure modes (consumer lag, contract mismatch, authorization failures).
  • Problem management process to remove recurring defect classes.

11.4 Change Management

11.4.1 Release Governance

  • Planned release calendar with architecture sign-off for contract changes.
  • Change advisory checkpoints for high-impact modifications.
  • Version lifecycle policy with clear deprecation communication.

11.4.2 Documentation Lifecycle

Maintain and regularly update:

  • Architecture decision records.
  • API and event contract documentation.
  • Operational runbooks and support playbooks.
  • Troubleshooting guides and known issue references.

11.5 Training and Enablement

11.5.1 Audience-Specific Training

  • Engineering teams: event design, contract evolution, and secure API implementation.
  • Operations teams: monitoring dashboards, alert response, and rollback execution.
  • Product and delivery stakeholders: rollout sequencing, readiness criteria, and KPI interpretation.

11.5.2 Adoption Support

  • Structured onboarding for new consuming teams.
  • Office-hours model during active migration phases.
  • Post-go-live knowledge transfer and continuous improvement reviews.

11.6 Continuous Improvement

  • Quarterly SLO and KPI review against business outcomes.
  • Recurring architecture health assessments.
  • Prioritized backlog for reliability, performance, and operability enhancements.