Comment by s5fs

Exploring a codebase tells you WHAT it's doing, but not WHY. In older codebases you'll often find weird sections of code that solved a problem that may or may not still exist. Like maybe there was an import process that always left three carriage returns at the end of each record, so now you got some funky "lets remove up to three carriage returns" function that probably isn't needed. But are you 100% sure it's not needed?

Same story with data models, let's say you have the same data (customer contact details) in slightly different formats in 5 different data models. Which one is correct? Why are the others different?

Ultimately someone has to solve this mystery and that often means pulling people together from different parts of the business, so they can eventually reach consensus on how to move forward.