Run instances with EC2 and Auto Scaling / ELB.
Use S3 storage to share data and EBS for persistent instance state.
Use IAM to manage users and control access, and Cloud Formation to manage resources.
Use CloudWatch to monitor your compute resources.
as root, on a CentOS 7.5 minimal install with a few IP addresses to spare
(CentOS 7.3/7.4 minimal may be used)
For a production install, follow the installation guide.