This week covered the core of AWS's compute and storage layers. EC2 instance families and purchase options (Day 1), the storage-selection principles behind EBS, Instance Store, EFS, and FSx (Day 2), the load-balancing tier of ALB, NLB, and GLB (Day 3), and ASG scaling policies and operational techniques (Day 4). These four are not independent services — they're the parts that make up a single architectural pattern.
The goal of this review isn't to memorize each one in isolation, but to build the ability to judge "which combination is optimal given the requirements." The SAA exam asks about trade-off judgment, not single-service trivia.