OYO interview questions

First round the interviewer asked basic system design questions along with REST api design. As per my knowledge, I answered the along the industry standards and I thought the interviewer is quite impressed by this too. But somehow the result was negative and to my surprise there was no feedback given to me by HR about what went wrong. The HR also was not at all professional and never came back even with the result of the interview. It was me who had to ask him about the result. Very bad interview process by sucha a big name in startup world.