Regeneron Research Associate III- Protein Biochemistry interview questions

First I was contacted by an HR and scheduled a phone interview. Waited for a few hours that day and didn't receive any calls, and no response trying to call or email back the person. Had to write to the candidate support mailbox to find out that HR already left the company, and got a rescheduled interview with another HR after that. Two phone interviews, first with the HR then the hiring manager. Called me a week later for the onsite interview. The onsite interview was a full day schedule. First a 30 min. presentation to the Protein Biochemistry group, then 1 on 2 interviews with the group members and 1 on 1 meetings with managers and a director. After that is a few months of waiting. The position is still remained opened and still interviewing after half a year.