Cardlytics Senior Software Engineer interview questions

Interview process takes very long period as it 3 months and till they prolonged last round and then informed to take other candidates. This is the worst experience i never had before. if the company is not happy with candidate they should inform before itself not like till all rounds completed.

Went through employee referral program. Had an unscheduled call with a project manager, he said he wanted to Catch me off guard (don't know why).Discussion with manager went very well. He liked my experience and replies to cultural questions and he decided to move with the next process. Next was a hacker rank test with 5 questions (2 sale, 3 algorithm based). Had 3 days to submit the test with test cases and production level code. Got all answers right but got a reply they will move with other candidates. Their expectations with coding round are not at all clear, if they are testing for quality of code then what are qualifying parameters are not stated at all.