Yes. It was a vital subsystem in a Smalltalk program. While most of the project had passable Object Oriented organization, this one subsystem had zero instance

Yes. It was a vital subsystem in a Smalltalk program. While most of the project had passable Object Oriented organization, this one subsystem had zero instance methods and zero instance variables. Instead, it was copy-pasta after slightly modified copy-pasta of these long methods that called each other recursively. Each one of these methods used a "merging" style algorithm that incremented 4 indexes into arrays, all the while executing deeply nested conditional logic. There were some smart cookies on the team, but we were all in fear of this code. The person who wrote it spent her days sitting in the cafe downstairs, reading novels. She'd check some logs, and occasionally come and yell at us for doing something wrong, which she would never explain. It turns out that the system had objects, but they were all embodied by consecutive spans of entries in those arrays. We went on a trek through the bowels of this corporation, asking around for documentation of the 3rd party software that used those sequences in those arrays, but no one had it, and that company no longer existed. If you tried to explain to her that Object Oriented code would have instance methods, she'd always bring up her PhD in math. A coworker of mine spent a week charting out one of those methods, and managed to rewrite it in 1/6th the line count, with no errors. However, that didn't really help, as it still implemented the same weird merging algorithm.