This post covers what I learned while preparing for AWS_SAA — IAM, EC2, Load Balancing, Auto Scaling, RDS, Route 53, S3, CloudFront, and messaging services. I'm writing this for engineers who already understand infrastructure, so I'm skipping the basics and going straight to what the exam actually tests. 1. IAM — It's About Least Privilege, Not Just Access IAM sounds simple until the exam starts testing edge cases. Here's what actually matters: The model: Users → Groups → Po...