The first was an HR interview, then the next is the supervisor, and then the department head. The first was a typical HR interview where you are asked questions about yourself, then questions about resume. Next is the the supervisor interview, where you are asked about your strengths, skills, willingness for the job, etc. The third is more technical wherein you are asked case study questions.

It was brief for hr interview. You should tackle your experience and skill set. Interviewers are kind, good listeners, attentive. But they tend to repeat phrases every answer you give.