AWS at 20: Under-the-Hood Improvements You Might Have Missed

AWS is nearly two decades old, and its foundational services have evolved significantly. Many older blog posts are outdated. This post highlights key improvements: EC2 instances now allow hot modification of security groups and IAM roles, resizing, and EBS volume changes; S3 offers read-after-write consistency, eliminates ACLs, defaults to block public access and encryption; networking improvements include Transit Gateway and faster CloudFront updates; Lambda boasts extended runtime, container image support, and performance enhancements; EFS and EBS performance is dramatically better; DynamoDB supports empty fields and offers more reliable performance; cost optimization involves Savings Plans replacing Reserved Instances, per-second billing, and robust cost monitoring tools; authentication relies on IAM roles over users, with IAM Identity Center replacing SSO; overall reliability has drastically increased.