Opening Scenario
Your service deployed fine, but now something is wrong. Latency is up. Users are reporting errors. Your on-call engineer is staring at a terminal wondering: which instance is struggling? When did it start? Is it getting worse? You have logs scattered across five EC2 instances and no central place to query them. You have no graphs of CPU, memory, or request rate. You're flying blind.
How do you see what's happening inside a distributed AWS-hosted system — right now, and historically?
Question Progression
1. How Do You See What Resources Are Doing?
Question: You have EC2 instances, RDS databases, and Lambda functions. You want a single place to track CPU utilization, error rates, and request counts over time. Where does that data live, and how do you access it?
Reasoning: Each AWS service generates operational data: CPU cycles consumed, bytes written, invocations triggered. If that data stays local to…
In the full tutorial
- When to Reach for CloudWatch
- Interview Follow-Ups