this question is related to 3-ties application design only, not 4+ tiered.
UI form - displays collection of clients info (this is the example I would like use as reference)
I am interested in how would what layer pass data up to the UI form? The important thing is that layer dependency cannot be mutual, meaning all three layers reside in a separate dll (exe). So no need for coding properties, methods, etc, I just need interfaces to see how would data flow.