Why this matters
Observability works best as a progression. Each level builds on the previous, though teams sometimes need to work on multiple levels at once.
Each level builds on the previous
Each level provides context for the next.
| Dependency | Why |
|---|
| Level 2 requires Level 1 | You can’t debug applications without seeing the infrastructure they run on |
| Level 3 requires Level 2 | You can’t trace requests without knowing which service is causing problems |
| Level 4 requires Level 3 | You can’t add custom instrumentation without understanding where to instrument |
The key question at each level
| Level | Focus | Key question |
|---|
| Level 1 | Infrastructure | “Is my infrastructure healthy?” |
| Level 2 | Services | “Which service is the problem?” |
| Level 3 | Transactions | “Why is this specific request slow?” |
| Level 4 | Application logic | “What’s happening in my code?” |