Merge branch 'lulalala-master-patch-32745' into 'master'

Add deep dive for multi-indices support

See merge request gitlab-org/gitlab!42351

doc/development/elasticsearch.md

@@ -15,6 +15,8 @@ the [Elasticsearch integration documentation](../integration/elasticsearch.md#en
 
 In June 2019, Mario de la Ossa hosted a Deep Dive (GitLab team members only: `https://gitlab.com/gitlab-org/create-stage/issues/1`) on GitLab's [Elasticsearch integration](../integration/elasticsearch.md) to share his domain specific knowledge with anyone who may work in this part of the code base in the future. You can find the [recording on YouTube](https://www.youtube.com/watch?v=vrvl-tN2EaA), and the slides on [Google Slides](https://docs.google.com/presentation/d/1H-pCzI_LNrgrL5pJAIQgvLX8Ji0-jIKOg1QeJQzChug/edit) and in [PDF](https://gitlab.com/gitlab-org/create-stage/uploads/c5aa32b6b07476fa8b597004899ec538/Elasticsearch_Deep_Dive.pdf). Everything covered in this deep dive was accurate as of GitLab 12.0, and while specific details may have changed since then, it should still serve as a good introduction.
 
+In August 2020, a second Deep Dive was hosted, focusing on [GitLab's specific architecture for multi-indices support](#zero-downtime-reindexing-with-multiple-indices). The [recording on YouTube](https://www.youtube.com/watch?v=0WdPR9oB2fg) and the [slides](https://lulalala.gitlab.io/gitlab-elasticsearch-deepdive) are available. Everything covered in this deep dive was accurate as of GitLab 13.3.
+
 ## Supported Versions
 
 See [Version Requirements](../integration/elasticsearch.md#version-requirements).