After applying I was contacted for an interview. They were fairly inflexible with available time slots so scheduling the interview took a couple of weeks. The interview lasted one hour and revolved around questions covering machine learning and statistics/time series. Upon completing the interview I did not hear back from the hiring manager. After 3+ weeks of no contact I reached out to him and was told that "he thought" someone had already told me my application was rejected. When asked about giving some feedback as to why I was rejected/ what I could improve upon there was no reply. I personally find this a bit odd and lacking of common courtesy when a candidate has spent time interviewing. Overall, the interview process seems a bit unprofessional and unstructured but otherwise normal.