The decision is actually 5 different variables. Types are: boolean, a decimal percent and integer being a monetary value. The domain is fintech: making a decision on how much money to give and some other aspects about the loan.
What you describe is the opposite of what I expect from (modern) fintech.
* no tests
* god method with no proper documentation/requirements
* no one actually understanding the function deciding how much money to send! Isn't this one of the core functionalities of fintech products?
This code was around before I joined. It started small, but more and more requirements were added until it became like that. Not much effort went into structuring it. Now it's my responsibility, and I'm trying to make it better for me and anyone who will have to deal with it in the future.