I'm aware of a few good options:
In production code for banks (or credit cards, ATMs, POS systems), what data type is actually used the most? I'm especially asking those who worked for banks.
EDIT: Super useful links for those with the same problem domain (needing to implement a "money" data structure that doesn't break).
EDIT for the fellow who said this is a duplicate question: This is a practical not a theoretical question of "what's the best". Read the unedited title of my question. I'm asking what people have seen first-hand in banks' codebases.
I know BigDecimal is "best" obviously, but nice APIs like that aren't available everywhere, believe it or not, and decimal libraries are expensive as opposed to ints.