Define the Global Search oncall escalation process

development/enablement/search/index.html.md.erb

@@ -96,6 +96,10 @@ We use the Fibonacci rating system to assign weights to Search issues. Below are
 | 3      | Medium effort |
 | 5      | High effort |
 
+### Oncall escalation coverage
+
+As the Global Search Team requires special domain knowledge, such as Elasticsearch, we borrow team members with this domain knowledge from other teams to cover the oncall escalation when we are under staffing especially during the holiday seasons. In general, we will follow the [dev oncall](https://about.gitlab.com/handbook/engineering/development/processes/Infra-Dev-Escalation/process.html#escalation-process) process. The Elasticsearch domain experts, which can be identified by domain_expertise on their profile, may be contacted when SRE and dev oncall engineers cannot resolve the production incidents. We don't expect the domain experts to work outside of their normal working hours. In case of emergency, we will follow the set of rules and best practices outlined in our [Incident Management](https://about.gitlab.com/handbook/engineering/infrastructure/incident-management/) handbook. In order to assist team members to catch up the latest development status and resolve potential incidents, we have created a [Global Search Incident Management document](https://gitlab.com/gitlab-org/search-team/training-materials/-/tree/main/2021-12-14-production-incident-management) as a reference.
+
 ### Common Links
 
 * [Global Search Team Milestone Board](https://gitlab.com/groups/gitlab-org/-/boards/1339901?label_name[]=group%3A%3Aglobal%20search)