The four services we saw throughout Week 7 — SQS, SNS, EventBridge, Kinesis — are all grouped under "Application Integration" in the console category, but the problems they solve inside that group are actually of different kinds. Mistaking them for services of the same grain just because they sit side by side on the same screen leads to picking the wrong tool, on the exam and in practice alike.
Fitting for the fifth day, this article doesn't pile on new services. Instead it once again organizes the models we saw over the past four days from the perspective of distributed-systems theory and scenario keywords, and untangles in one pass the decision axes that most often confuse people on the exam