I Made a Classic Refactoring Mistake

💡 Learn how to design great software in 7 steps: https://arjan.codes/designguide. In my previous video on refactoring complicated business logic, I made several mistakes and you spotted them. In this video, I go through what went wrong, why these kinds of errors are so easy to introduce during refactoring, and the traps developers fall into when they assume they understand the rules encoded in existing code. We’ll look at how tests, coverage, and “cleaner” code can still hide logical mistakes, and why there often is no single ground truth when dealing with business logic. Original video where I covered the refactoring: https://youtu.be/mH7e7fs9gaE 🎓 ArjanCodes Courses: https://www.arjancodes.com/courses. 💬 Join my Discord server: https://discord.arjan.codes. ⌨️ Keyboard I’m using: https://amzn.to/49YM97v. 🔖 Chapters: 0:00 Intro 0:27 Context 1:35 Three mistakes 4:27 A few other issues and remarks 9:13 Traps / what is the ground truth? 14:40 Final thoughts #arjancodes #softwaredesign #py