Over one week we examined CloudWatch, X-Ray, CloudTrail, EventBridge separately. Yet these four are actually one question answered from four angles: "What's happening in the running system, how do we know, and how do we respond?" This final day doesn't just review individual services; it shows how these four interlock into one observability picture, then validates that understanding through comprehensive scenario questions.
The most common exam mistake is memorizing "name → function." Instead, two axes create coordinates revealing why each tool sits where it does.