HR does initial screen. Hiring leader does second screen. Then you meet a couple of his colleagues that you'd work with most or that he/she respects most. Then you meet his boss. Then you meet his boss' boss for final interview. So that's 5 interviews to get one job. It's a long road so be patient and persistent and prepared. They'll ask you to tell you about your background, what skills are transferrable to job, previous experiences that relevant to job, what you'd do if hired, what the biggest challenges are, etc...