HR just interacted over mail and never called at any stage of interview. First technical screening happened after which 6 interviews were scheduled(disregarding my availability for all 6). First round interviewer was quite rude and lacked technical details himself. Hiring manager directly told about on call rotations, night shifts, US shifts and team culture. Thankful for being so transparent. After listening about team culture, requirement and meeting the panel I am happy that I didn't receive offer.