A three-line order could be sourced from either of two warehouses. How do you decide where it ships from, and what happens when one line falls through?

Short answer

Allocation is a cost minimisation over shipping, split-parcel cost and delivery promise, evaluated per line rather than per order; the design that survives is one where every line carries its own state, cancellation is a race against the pick face, and a shortfall is a normal outcome with a defined path.

Keep order management explicit in the answer because that is the concept the interviewer is actually trying to test. A good order management explanation names the trade-off, the failure mode, and the evidence you would use before choosing. Use order management once more at the decision point so the answer reads as judgement rather than a detached example.

Keep order management explicit in the answer because that is the concept the interviewer is actually trying to test. A good order management explanation names the trade-off, the failure mode, and the evidence you would use before choosing.