Understand the system behind the incident.

Build causality progressively

1. DEPENDENCY

   Checkout ─────────▶ Payment

2. +

   TEMPORAL ORDER

   Checkout degraded 6 seconds earlier

3. +

   TELEMETRY EVIDENCE

   Failures propagate along dependency

4. +

   CHANGE

   Checkout deployed 83 seconds earlier

5. ↓

   CAUSAL HYPOTHESIS

   Checkout likely contributed to Payment degradation.

Causal edges are hypotheses—labeled likely, never declared fact.

Edge epistemology

• Observed relationship

  Thin solid edge

  Checkout ─── calls ───▶ Payment

• Inferred causal relationship

  Heavier/double edge + label

  Checkout ══ likely propagation ══▶ Payment

• Unknown / unverified relationship

  Dashed edge

  Checkout ┄┄ possible ┄┄▶ Inventory