Every operations team faces this moment: early morning security request—"patch log4shell on all EC2 immediately." Running SSM Patch Manager reveals agent missing on some, failed boot dependencies on others, workload stalling during patching. Operator resolves: "next time, build new AMI and bulk-replace ASG." That's the Golden AMI pattern; automating that resolve is EC2 Image Builder.
This article examines why Image Builder isn't mere Packer replacement but "AWS-native immutable infrastructure pipeline," how Recipe, Component, Pipeline separate responsibilities, and how Golden AMI flows to operations ASG (SSM Parameter Store + Launch Template {{resolve:ssm:...}})