Zalando Machine Learning Specialist interview questions

I applied for zalando's machine learning position this year, however i failed to pass the first interview that was launched through Skype. The company's recruiter contacted with me in 3 or 4 days after I applied and we agreed to have an interview after a week interval. During this interval I prepared for a first interview session that would probably ask me question about my CV and background experience, however the interviewer started immediately with a research problem discussion and skipped this initial questions. He was polite and strict. The interview lasted exactly 40 minutes and I was dissapointed that I did not satisfy the standards of this company. After an interval of 5 days they answered me that I was rejected with a polite nevertheless way.