# Backfills - The Necessary Evil of Data Engineering

DevFeed: [Backfills - The Necessary Evil of Data Engineering](<https://devfeed.tech/articles/backfills-the-necessary-evil-of-data-engineering-37138.md>)

Original publisher: [Read original article](<https://seattledataguy.substack.com/p/backfills-the-necessary-evil-of-data>)

Author: SeattleDataGuy

Published: 2026-02-23T23:37:52Z

Content type: tutorial

Language: en

Sources: [SeattleDataGuy's Newsletter](<https://devfeed.tech/sources/seattledataguy-s-newsletter.md>)

Topics: [data-engineering](<https://devfeed.tech/topics/data-engineering.md>), [Data pipelines](<https://devfeed.tech/topics/data-pipelines.md>), [data](<https://devfeed.tech/topics/data.md>), [datasets](<https://devfeed.tech/topics/datasets.md>), [systems](<https://devfeed.tech/topics/systems.md>)

Tags: [bug](<https://devfeed.tech/tags/bug.md>), [data-engineering](<https://devfeed.tech/tags/data-engineering.md>), [data-pipelines](<https://devfeed.tech/tags/data-pipelines.md>), [data-type](<https://devfeed.tech/tags/data-type.md>), [databases](<https://devfeed.tech/tags/databases.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [pipelines](<https://devfeed.tech/tags/pipelines.md>), [schema](<https://devfeed.tech/tags/schema.md>)

## AI overview

This article explains why data teams perform backfills and why data engineers often dislike them. It describes backfills as rerunning or rebuilding tables and pipelines to account for corrected source data, pipeline bugs, schema changes, logic changes, or required data-type conversions.

## Source excerpt

Why backfills happen, why we hate them, and how to handle them without breaking trust