---
title: "Discussion on \"Why Ad Reports Don't Match Bidder Logs, and Who Can Rebuild the Pipeline\" | Hashnode"
description: "Discussion on \"Why Ad Reports Don't Match Bidder Logs, and Who Can Rebuild the Pipeline\". Originally published at ambrain.org.\nAd reports and bidder logs disagree for one of two reasons: events are lost on the way to the reports, or the two sides count them by different rules. One recount"
url: "https://hashnode.com/posts/why-ad-reports-don-t-match-bidder-logs-and-who-can-rebuild-the-pipeline/6ad0a3a12d1ef8f019eb9e3b"
---

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Discussion

# [Why Ad Reports Don't Match Bidder Logs, and Who Can Rebuild the Pipeline](https://ambrain.hashnode.dev/why-ad-reports-don-t-match-bidder-logs-and-who-can-rebuild-the-pipeline?utm_source=hashnode&utm_medium=feed)

Originally published at ambrain.org. Ad reports and bidder logs disagree for one of two reasons: events are lost on the way to the reports, or the two sides count them by different rules. One recount

Oct 15 · 12 min read · ambrain.hashnode.dev  
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-   [#adtech](https://hashnode.com/tag/adtech)
-   [#programmatic-advertising](https://hashnode.com/tag/programmatic-advertising)
-   [#data-engineering](https://hashnode.com/tag/data-engineering)
-   [#analytics](https://hashnode.com/tag/analytics)

## Written by

[amBrain](https://hashnode.com/@ambrain)

@ambrain · Yerevan, Armenia

  
[View profile](https://hashnode.com/@ambrain)

Engineering partner in three areas: AdTech, FinTech & Trading, and GenAI. Hot paths in Rust. ambrain.org

Engineering company in Yerevan, Armenia (since 2019). Three areas: AdTech, FinTech & Trading, and GenAI. We build and fix real-time systems; performance-critical parts are written in Rust. ambrain.org

## Responses 1

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[StackShortlist](https://hashnode.com/@veristria)

[Oct 17](https://hashnode.com/posts/why-ad-reports-don-t-match-bidder-logs-and-who-can-rebuild-the-pipeline/6ad0a3a12d1ef8f019eb9e3b/comment/6ad30fd4ddcd258bc3f7397c)

Running the recount on auction IDs before hiring anyone is the right order, since a new pipeline fixes lost events and does nothing for two sides that close the day in different time zones. Counting again a day later matters too, because a late event landing in another hour looks like loss on the first pass. When the missing share rises at peak, which seam usually shows it first in these rebuilds, the collector or the load into ClickHouse?