Question 610
For Mercury Travel Tech, the engineer must verify a remediation with measured evidence, not just a deployment claim. The original failure was: A production endpoint upgrades its model in place with no isolated candidate environment, making rollback dependent on restoring files manually. Which independently observable result best verifies that the remediation works?
Explanation
Correct Answer
An injected failure shifts traffic back to the prior environment without model artifact changes. This controlled observation specifically validates the proposed remedy: Use separately versioned blue-green serving environments and a reversible traffic switch. It addresses the documented failure at Mercury Travel Tech: A production endpoint upgrades its model in place with no isolated candidate environment, making rollback dependent on restoring files manually.
Incorrect Answers
Measured prediction latency meets the SLO and requested explanations remain complete and reproducible. This is evidence for a different corrective change: Separate or selectively run explanation workloads when policy permits while preserving required auditability. That other change addresses: A regulated prediction endpoint recomputes expensive explanations synchronously for every low-risk request and breaches the latency SLO. It does not validate the specific Mercury Travel Tech remediation for: A production endpoint upgrades its model in place with no isolated candidate environment, making rollback dependent on restoring files manually. The necessary check instead is: An injected failure shifts traffic back to the prior environment without model artifact changes.
Stage-level traces show the preprocessing delay reduced while prediction parity remains within tolerance. This is evidence for a different corrective change: Profile preprocessing separately and move appropriate repeatable transformations or governed feature materialization closer to serving. That other change addresses: A live model's preprocessing stage performs remote joins on every request and dominates latency even though the core inference is fast. It does not validate the specific Mercury Travel Tech remediation for: A production endpoint upgrades its model in place with no isolated candidate environment, making rollback dependent on restoring files manually. The necessary check instead is: An injected failure shifts traffic back to the prior environment without model artifact changes.
A source update becomes visible to an authorized online inference request within the freshness objective. This is evidence for a different corrective change: Serve appropriately fresh governed online features through Agent Platform Feature Store or an equivalent controlled lookup. That other change addresses: An online model uses dynamic customer features but reads yesterday's exported CSV snapshot for every prediction, causing stale recommendations. It does not validate the specific Mercury Travel Tech remediation for: A production endpoint upgrades its model in place with no isolated candidate environment, making rollback dependent on restoring files manually. The necessary check instead is: An injected failure shifts traffic back to the prior environment without model artifact changes.