Your duplicate check cannot prove absence. Ours returned 404 for the post we had just published.

Twenty-three minutes prior to the measurement, the outlet released an article asserting that human approval gates are typically not judgments. These gates involve manual verification of whether a piece of content already exists. To address this, the team moved the human approval gate into code. The team then ran a query against their system, which unexpectedly returned a 404 error, indicating that the article they had just published was not found.

In six separate attempts within approximately four minutes, all authenticated read requests produced the same result. The investigation focused on a single article published that morning. Despite a written prescription stating that publication should not be judged by a list, but rather using the single-item endpoint or article URL, the gate failed.

The short-term failure highlights the limitations of checking for the absence of evidence. The team emphasizes that one layer confirming absence is sufficient to establish it, while multiple layers affirming absence is necessary to confirm non-existence. The findings underscore the challenges of establishing absence in asynchronous systems and the potential pitfalls of designing gates that only confirm presence.