The main codebase a team I work with uses. They’re a data science team mostly but the main “data processing engine” that they solely rely on was written by a d

The main codebase a team I work with uses. They’re a data science team mostly but the main “data processing engine” that they solely rely on was written by a dude who split right as he “finished it”. No one knows how it really works. Black box style. Has been “the way” for 5 years. I’m not sure if no one cares, or no one cares to care, but they don’t seem to want to change it. Maybe it works, but also funny how many business critical decisions are made based on the code that everyone has only ever “just trusted”.