The professional-level architecture exam. Every question is a long scenario where two or three answers would work and exactly one satisfies a constraint buried in the third sentence. Most of the preparation is learning to find that constraint, not learning new services.
Domain weights: organizational complexity 26%, design for new solutions 29%, continuous improvement 25%, migration and modernization 20%.
Engineers who already run AWS in production tend to walk in strong on VPC design, IAM mechanics, containers, infrastructure as code, and observability. The exam punishes that profile in three places, and that is where a study hour pays best:
- Migration tooling. Application Discovery Service, Migration Hub, Application Migration Service, DMS with SCT, Snow Family sizing, and the 7Rs vocabulary. A fifth of the exam, and mostly service knowledge you cannot reason your way to.
- Hybrid networking specifics. Direct Connect resiliency models, virtual interface types, Route 53 Resolver endpoint direction, and Transit Gateway route table propagation and association.
- Disaster recovery by the numbers. The four named strategies and the RTO and RPO each one actually delivers.