Hailo Technologies interview questions

Quick phone interview, then on-site interview with manager and a PM from another group. The interview went well and seemed like a sure thing but a few days later they came back with a no and declined to give even a hint of what didn't work.

3 interviews, first is specific with Hardware questions, technical questions. second interview with VP, included of sharing debugs, special technical experienced i faced in the past job and how i deal with it. the last one is with HR and CEO