Behind the Book · Publisher’s note

Why the decision
comes first.

A service name can be the start of an answer. It is rarely the whole answer.

A useful architecture discussion asks what the system needs to do, which constraints matter, and what happens when those constraints pull in different directions.

That is the approach readers will find in AWS Architecture Decisions by Ethan H. Arlen. Fictional architecture reviews make room to compare alternatives. Worked trade-offs and diagrams give the decisions context. Original questions and explanations give readers a way to check their reasoning.

Two volumes, different starting points.

Volume I covers architecture, data, AI and security. Volume II focuses on economics, resilience, operations and practice. Readers can begin with the subjects most relevant to their work or study, then use the companion volume to extend that view.

Make the reasoning your own.

Before reading an explanation, write down the constraints you noticed and the choice you would make. Then compare your reasoning with the rationale and current AWS documentation. The point of the exercise is to explain a decision, including its limits.

These are independent educational books. The scenarios are fictional and the questions are original study exercises, not official AWS exam items. No exam result is guaranteed.