Drawing fund-flow diagrams auditors can read

Pretty component diagrams rarely answer the question auditors ask: whose money is this at each step, and who can move it?

Label custody explicitly

For every arrow that represents value, annotate which legal entity holds the funds and which licence or arrangement authorises the movement. If you cannot label it, the design is not finished.

Separate control planes

Show customer interfaces apart from settlement operators and apart from reconciliation jobs. Collapsing them into “backend” hides segregation problems until a partner due-diligence questionnaire arrives.

Keep a boring legend

Use the same colours and shapes across documents. Dramatic redesigns of the diagram style look creative and destroy continuity in your compliance file.