“LINE Messenger” is a messaging service used daily by hundreds of millions of people worldwide. Therefore, it is crucial to provide an infrastructure and network environment that guarantees performance and reliability, allowing users to send and receive messages 24/7. Recently, a project was initiated to migrate part of our global infrastructure from on-premises to the AWS environment, and we successfully completed the service migration. During this project, we ensured continuous operation without compromising stability while maintaining a higher level of security. I would like to share our experience of this migration with you.