Frankenstein Laptops, Zombie Code, and SAP’s Haunted Castle

Early in my career, I was asked to dissect a user exit that transformed deliveries into billing documents. The exit had clearly been enhanced multiple times over the years — but the documentation was ancient, incomplete, and mostly useless. At the time, my ABAP skills were still developing, but even I could spot something off. The code was trying to reflect business processes that didn’t seem to exist anymore. When I asked around, it turned out I had stumbled upon something every SAP consultant eventually meets: zombie code. Business logic that no one uses, but no one dares to remove. It’s too risky. It might be wired into something else. So it stays. Undead. Untouched. Slowly poisoning maintainability. That user exit taught me more about legacy risk than any training ever could.

Little did I know, that shambling chunk of zombie code was not the only monster lurking in the halls of our ERP. In fact, it was just one inhabitant of what I now fondly call my haunted SAP castle. (Don’t worry, I brought a flashlight and some sage.) Perhaps a better mascot for these unwieldy systems is Dr. Frankenstein’s famous creation — initially ingenious, now terrifying. Before we venture deeper into this spooky analogy, let’s set our compass with a few key lessons:

Key Takeaways

1. Not all custom code ages gracefully.
2. Clean Core is a cultural shift, not a technical one.
3. S/4HANA is a rare opportunity to rebuild right.
4. Testing Clean Core now can prevent pain later.
5. Frankenstein systems are a choice — not a fate.

Now, with these in mind, follow me into the depths. Cue thunder and lightning.