Public question and preparation brief

Difficulty

Intermediate

Time

45–60 min

Stage 01

Reconcile spend with requests

The invoice and the request counts disagree about how much work actually happened. List the quantities you would reconcile first, and say which two could both be correct and still explain the gap.

What to demonstrate: Does the candidate start from an accounting identity rather than a favorite cause?

Stage 02

Separate the mechanisms

Longer outputs, retried calls, cache misses, a rerouted model, extra tool invocations, and concurrency that grows when responses slow down each move spend for a different reason. Pick two of them and describe the measurement or experiment that would separate them.

What to demonstrate: Is every hypothesis paired with a test that could actually reject it?

Stage 03

Question the traffic denominator

Part of the increase may come from callers that never appear in the traffic dashboard. Explain how you would discover those callers and attribute their share of spend before tuning anything else.

What to demonstrate: Does the candidate check the denominator before optimizing efficiency?

Stage 04

Choose one fix

You can ship one change this week: a routing rule, a cache repair, or a cap on tool calls. Choose one, state the recovery you expect, and name the check that would show the cost moved elsewhere instead of disappearing.

What to demonstrate: Can the candidate commit to an action with an expected effect and a falsifying signal?