Add instructions for tier 2 oncall onboarding

content/handbook/engineering/infrastructure/incident-management/_index.md

@@ -165,6 +165,11 @@ Responsibilities of this role:
 
 The EOC Coordinator will work closely with the Ops Team on core on-call and incident management concerns, and engage other teams across the organization as needed.
 
+### Tier 2 Oncall
+
+Tier 2 on-calls are established to provide subject matter expertise when required. Additional teams may be added when appropriate.
+To initiate onboarding of a new tier 2 team, follow the guidelines in [Tier 2 Oncall Onboarding for teams](/handbook/engineering/infrastructure/incident-management/tier2-oncall-onboarding)
+
 ### Communications Manager on Call (CMOC) Responsibilities
 
 For serious incidents that require coordinated communications across multiple channels, the Incident Manager will rely on the CMOC for the duration of the incident.

content/handbook/engineering/infrastructure/incident-management/tier2-oncall-onboarding.md

+---
+title: "Tier-2 Oncall"
+---
+The Tier-2 SME on-call program enhances incident response by establishing a second tier of specialized support to complement the existing SRE EOC (Engineering On-Call) rotation. Subject Matter Experts (SMEs) provide domain-specific knowledge to help resolve complex incidents faster, improve MTTR (Mean Time To Recover), and increase ownership and accountability for service reliability.
+
+## Expectations
+
+- Respond when paged by:
+  - Tier-1 SRE EOC
+  - Security
+  - Self-Managed Support
+- Assist with complex, domain-specific incidents that Tier-1 cannot resolve independently
+- Maintain a 24/7/365 rotation with reliable coverage across time zones
+- Acknowledge pages within 15 minutes and have a clear escalation path if the primary responder is unavailable
+- Help define and maintain:
+  - Escalation rules for your domain
+  - Documentation and runbooks
+
+## Onboarding Process for Teams
+
+1. **Define SME group**
+   - Identify team members who will participate in the rotation
+   - Consider legal and employment restrictions for out-of-hours coverage
+2. **Create onboarding issue**
+   - Use the [Team incident onboarding template](https://gitlab.com/gitlab-com/gl-infra/production-engineering/-/issues/new?description_template=team-incident-onboarding)
+   - Document escalation criteria and severity levels
+3. **Set up on-call rotation**
+   - Configure schedules in incident.io
+   - Ensure pager settings and notification rules are set for each member of the new rotation.
+4. **Document escalation procedures**
+   - Define escalation chain for unacknowledged pages (who is escalated to if no one responds within 15-minute period)
+5. **Complete training**
+   - Ensure all participants understand their role
+   - Review incident response procedures
+
+## Next Steps
+
+1. Double check your schedule to ensure coverage during holidays and team events