Recruitment and evaluation systems land in the high-risk tier, which means the obligations attach to how you build, not just to what you publish.
The practical consequence for an engineering team is that three things stop being optional: a record of what data trained or prompted a decision, a human review path that is real rather than nominal, and documentation you could hand an auditor without a week of archaeology.
None of that is expensive if it is designed in. All of it is expensive to retrofit, because the record you need is the one you did not keep.