In their blog, Annie Hansen and Stef Nestor provide a comprehensive guide on how to connect a custom AWS S3 snapshot repository to Elastic Cloud for backing up Elasticsearch cluster data. They detail the step-by-step process starting with the creation of an AWS S3 bucket and setting up the necessary AWS Identity and Access Management (IAM) policies and users to ensure proper authorization. The guide explains how to generate and securely store access keys needed for connecting the bucket to the Elasticsearch cluster, and it covers the registration of the AWS S3 repository through Kibana. Special attention is given to maintaining secure settings, verifying repository connections, and the importance of managing snapshot lifecycle to ensure data integrity and prevent accidental overwrites. Overall, the blog emphasizes the flexibility and reliability of using both built-in and custom backup solutions within Elastic Cloud environments.