You need to introduce postmortems into your organization during the holiday shopping season.

Monitor latency of your services for average percentile latency.

Review your increased capacity requirements and plan for the required quota management.

Create alerts in Cloud Monitoring for all common failures that your application experiences.

Ensure that relevant system metrics are being captured with Cloud Monitoring and create alerts at levels of interest.

Configure Anthos Service Mesh on the application to identify issues on the topology map.