Zombies eating your AWS bill?

The text discusses an efficient process used by LaunchDarkly to deploy new versions of their services on Amazon EC2 instances, using Ansible for orchestration and maintaining a 'cattle, not pets' mindset. It also highlights the issue of "zombie" instances that can accumulate over time due to errors in the deployment process, which may go unnoticed by monitoring systems as they do not raise any alarms. To address this problem, the author wrote a Python script that detects zombie instances and publishes an alert to an SNS topic. The script assumes the use of tags on EC2 instances and load balancers for discovering live instances. Instructions are provided for setting up the script in one's own environment, including modifying the custom.py file with appropriate settings and running the deploy_lambda_function.sh script to package and deploy the Lambda function. The author also mentions that additional setup is required for adding subscribers to the SNS topic based on individual needs.