Fun semi-related story. Way back when, while I was squishing some Y2K bugs for a Saudi bank that catered to high net-worth individuals I was asked to look into

Fun semi-related story. Way back when, while I was squishing some Y2K bugs for a Saudi bank that catered to high net-worth individuals I was asked to look into why the AS400==>>db==>>Excel spreadsheet was "showing something screwy every now and then". Spoiler Alert: It was a SMALLINT error that was 'patched' by someone previously (legacy code) that worked around the bug by rounding account balances to the Million (since it was a reporting function rather than an accounting function it was a 'sort of ok' hack). The bug re-appeared as undefined behaviour when transaction and or account balances went in to the billions.