The hiring process involved 5-6 rounds, including an on-site interview (interview with line managers, written test, shadowing test, interview with CEO/COO at the end) that exceeded 4 hours with long waiting time between rounds.
Appreciated the HR's effort to maintain the smooth hiring process with prompt response in email. However, one of the interviewers was frequently distracted by the phone during the interview, it's quite unprofessional and disrespectful.