Xerox Mechanical Engineer interview questions

Contacted by HR first, then spoke to the hiring manager for a phone interview. After about one month, I was brought in for an on-site panel interview that took about 6 hours. Each panel interview was with two people for one hour. They mostly asked technical and behavioral questions. Interviews seemed pretty long and in-depth for an early career position. HR was extremely unprofessional and completely ghosted me after the on-site interview. All of my phone calls were completely ignored. I can take the hint, but it makes your organization look pretty disorganized.