Bring your own IP addresses (BYOIP) You can bring part or all of your publicly routable IPv4 or IPv6 address range from your on-premises network to your AWS account. You continue to own the address range, but AWS advertises it on the internet by default. After you bring the address range to AWS, it appears in your AWS account as an address pool. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-byoip.html AWS Transfer for SFTP enables you to easily move your file transfer workloads that use the Secure Shell File Transfer Protocol (SFTP) to AWS without needing to modify your applications or manage any SFTP servers.
https://aws.amazon.com/about-aws/whats-new/2018/11/aws-transfer-for-sftp-fully-managed-sftp-for-s3/

Migrating the containers that run the application to AWS Fargate for Amazon Elastic Container Service (Amazon ECS) will meet the requirement of not administering the Docker hosting environment. AWS Fargate is a serverless compute engine that runs containers without requiring any infrastructure management3.
Creating an Amazon Elastic File System (Amazon EFS) file system and adding a volume to the Fargate task definition to point to the EFS file system will meet the requirement of low-latency storage that will automatically scale throughput to meet increased demand. Amazon EFS is a fully managed file system service that provides shared access to data from multiple containers, supports NFSv4 protocol, and offers consistent performance and high availability4. Amazon EFS also supports automatic scaling of throughput based on the amount of data stored in the file system5.

Adding an accelerator in AWS Global Accelerator will enable improving the performance of the APIs for local and global users1. AWS Global Accelerator is a service that uses the AWS global network to route traffic to the optimal regional endpoint based on health, client location, and policies1. Configuring the ALB as the origin will enable connecting the accelerator to the ALB that exposes the APIs2. AWS Global Accelerator supports non-standard REST methods such as LINK, UNLINK, LOCK, and UNLOCK3.

https://docs.aws.amazon.com/codedeploy/latest/userguide/integrations-aws-auto-scaling.html

* Create a Transit Gateway:
* In the shared services account, create a new AWS Transit Gateway. This serves as a central hub to connect multiple VPCs, simplifying the network topology and management.
* Configure Transit Gateway Attachments:
* Attach the VPC containing the Aurora DB cluster to the transit gateway. This allows the shared services VPC to communicate through the transit gateway.
* Create Resource Share with AWS RAM:
* Use AWS Resource Access Manager (AWS RAM) to create a resource share for the transit gateway. Share this resource with all development accounts. AWS RAM allows you to securely share your AWS resources across AWS accounts without needing to duplicate them.
* Accept Resource Shares in Development Accounts:
* Instruct each development team to log into their respective AWS accounts and accept the transit gateway resource share. This step is crucial for enabling cross-account access to the shared transit gateway.
* Configure VPC Attachments in Development Accounts:
* Each development account needs to attach their VPC to the shared transit gateway. This allows their VPCs to route traffic through the transit gateway to the Aurora DB cluster in the shared services account.
* Update Route Tables:
* Update the route tables in each VPC to direct traffic intended for the Aurora DB cluster through the transit gateway. This ensures that network traffic is properly routed between the development VPCs and the shared services VPC.
Using a transit gateway simplifies the network management and reduces operational overhead by providing a scalable and efficient way to interconnect multiple VPCs across different AWS accounts.
References
* AWS Database Blog on RDS Proxy for Cross-Account Access#48#.
* AWS Architecture Blog on Cross-Account and Cross-Region Aurora Setup#49#.
* DEV Community on Managing Multiple AWS Accounts with Organizations#51#.