# Lessons From 9 More Years of Tricky Bugs

DevFeed: [Lessons From 9 More Years of Tricky Bugs](<https://devfeed.tech/articles/lessons-from-9-more-years-of-tricky-bugs-29066.md>)

Original publisher: [Read original article](<https://henrikwarne.com/2025/06/15/lessons-from-9-more-years-of-tricky-bugs/>)

Author: Henrik Warne

Published: 2025-06-15T08:17:28Z

Content type: opinion

Language: en

Sources: [Henrik Warne](<https://devfeed.tech/sources/henrik-warne.md>)

Topics: [debugging](<https://devfeed.tech/topics/debugging.md>), [coding](<https://devfeed.tech/topics/coding.md>), [Testing](<https://devfeed.tech/topics/testing.md>), [CSV](<https://devfeed.tech/topics/csv.md>), [Database](<https://devfeed.tech/topics/database.md>)

Tags: [blog](<https://devfeed.tech/tags/blog.md>), [bugs](<https://devfeed.tech/tags/bugs.md>), [ci](<https://devfeed.tech/tags/ci.md>), [code](<https://devfeed.tech/tags/code.md>), [coding](<https://devfeed.tech/tags/coding.md>), [csv](<https://devfeed.tech/tags/csv.md>), [database](<https://devfeed.tech/tags/database.md>), [debugging](<https://devfeed.tech/tags/debugging.md>), [errors](<https://devfeed.tech/tags/errors.md>), [learning](<https://devfeed.tech/tags/learning.md>), [programming](<https://devfeed.tech/tags/programming.md>), [testing](<https://devfeed.tech/tags/testing.md>)

## AI overview

A retrospective review of tricky bugs tracked since 2002 examines lessons from coding, testing, and debugging. Examples include empty values, date logic, legacy data formats, aliased dictionaries, and uncommitted local changes.

## Source excerpt

Since 2002, I have been keeping track of all the tricky bugs I have come across. Nine years ago, I wrote a blog post with the lessons learned from the bugs up till then. Now I have reviewed all the ... Continue reading ->