An on-call engineer can tag responders to an incident. These responders are then notified by Zenduty according to their notification rules. They can acknowlege and resolve the incidents. This features makes it easier for the on-call engineers to loop in people with the right expertise into the incident when they may themselves be unsure of how to triage it themselves. Multiple responders can be tagged at once, and they will receive notifications from Zenduty until the incident is acknowledged.
To add a responder, simply click on the "Responders" tab in incident details. Start typing the name of the responder you want to tag. Select the name from the dropdown and click "Add".