Over a decade ago, I was working at a company that sold insurance software. It seemed like the database got designed only about halfway, then the rest of everything was kludgy hacks. Like, if this certain number field is negative, then it's really the absolute value, but it meant that this row was the active one for the account, unless the next timestamp in the same account has a value "i" in this other column...

On and on like that. In fact, there were entire internal courses to teach these kludgy schemes, and they had fancy sounding official names. (Yes, entire week long courses, not just 1-day workshops.)