The banking, finance, and corporate accounting world and their practices would shock most devs to the core. Most people just assume that certain controls are being enacted with precision. Things like: customer account reconciliation, bank account reconciliation, etc.

Most of the time people just aggregate values and never inspect the detail. They record those aggregates in the GL and move on. I have never seen granular recon. That is why embezzlement is only discovered by accident years later.