Wealthsimple Senior Java Engineer interview questions

Got approached by a friendly CxO after posting on HackerNews' Who wants to be hired topic. Had a brief conversation with him, describing my experience and sent my resume. He referred me to an open position. An HR person got in touch via email to set up a phone call. The HR person was super friendly and the conversation went well. Got asked about current projects, what languages I was comfortable working with, the usual stuff. The feedback came less than a week later, stating that they weren't going to proceed with the process with me. I asked about a feedback but never got one.