CARIAD Senior Development Engineer interview questions

Had 4 rounds - Technical Round (taken by team lead) Architect Round (taken by Principal Architect) Managerial Round (Senior Director) HR Round Cleared first 2 rounds which was difficult IMHO and was very good. but got rejected in Managerial round with no feedback as to why, and same day scheduled HR round was cancelled. Prior to that 4 different HR have been communicating during process and once Managerial round is over, no one received the call, called back or reply on email. Pathetic Experience. Didn't expected after clearing 2 most important and difficult TECH ROUNDS.