The pattern repeats with remarkable consistency across large organisations. A small team builds something genuinely impressive in a few weeks, usually against exported sample data on a laptop or in a sandbox account, and the demonstration goes well enough that the project gets funded properly. The trouble begins at exactly the point where the system has to touch production data, because that is when the pilot stops being a technical exercise and becomes an organisational one, and almost nothing about the prototype prepared anybody for that conversation.
What surfaces at that stage is a set of questions the prototype never had to answer. Where does the data physically reside while the model processes it, and does that satisfy the jurisdiction your regulator cares about. Which role can see which records, and does the system honour the entitlements your identity provider already enforces or does it quietly bypass them. When somebody asks in eighteen months why a particular decision was made, can you reconstruct it. And if the answer to any of those is uncomfortable, the project does not usually fail loudly, it simply stops moving while everybody waits for somebody else to take the risk.
Our view is that these questions are architectural rather than administrative, which means they cannot be resolved by adding a policy document to a system that was designed without them. A system that sends your data to a third party cannot be made compliant by promising not to look at it, and a system that maintains its own separate permission model cannot be made safe by documenting who is supposed to have access. Designing for the constraints from the beginning costs slightly more in week two and saves the entire project in month four, which is the trade we consistently recommend.