You tried to integrate two systems including both the frontend and backend in a stack. These systems don’t store any state inside. All of the state information is stored in a DynamoDB table. You have launched each of the systems with separate AMIs.

Answer options:

A.Use Route53.
B.Use Blue/Green deployment strategy by creating new Auto Scaling groups with the new AMIs.
C.Modify the AMIs used by the existing Auto Scaling groups and adjust the desired number of Auto Scaling group to deploy the new AMIs in the new instances.
D.Use Amazon CloudFront with access to the frontend server with origin fetch.
E.Use Amazon SQS between the frontend and backend subsystems.

Answer – B and C
Option A is incorrect because Route53 cannot be used to deploy the fixes.
Option B is CORRECT because Blue/Green deployment strategy can deploy new versions of AMIs without service disruption.
Option C is CORRECT because you can modify the AMI used by the Auto Scaling group and adjust the desired number of the ASG to launch new instances with the new AMI.
Option D is incorrect because deploying CloudFront is not needed in this situation.
Option E is incorrect because SQS does not help to deploy the new fix.
Reference:
https://d1.awsstatic.com/whitepapers/AWS_Blue_Green_Deployments.pdf