lastminute.com interview questions

They given design document to prepare Interviewer was not keen on design done. But to ask question which was irrelevant when design was given for payment system. Why I will think of Fraud detection service to be applied in while adding to cart. This was in question which revolved in interview A B C D E are services A gets a payload of hotel booking info. Then it should send it to B and C, for B it will send only booking info. To C it will send hotel name and details. C will send hotel reviews and comments to D. E service will observe all these things and records each change to any of info.