BRAIN CORP Senior Electrical Engineer interview questions

Company ghosts candidates during onsite interview scheduling. Phone interview with HR describing company and gathering candidate information, take home technical design problem, technical phone interview and failed onsite interview. Phone interview with HR was standard. Typical questions about candidate (salary requirements) and then them selling the company. Take home design problem asked to design a level shifter for a UART. Technical phone interview was interesting. I was asked to block diagram an Ethernet interface and explain all components. I have 4 years experience designing these interfaces so I flew through the question in 5 minutes. There was no further questions so the remaining time was spent with me asking questions about the company/product. The interview process became very unprofessional when I was asked to come onsite, scheduled an interview and then was asked to reschedule. After being asked to reschedule the hiring personnel ghosted me. I find this to be odd and extremely unprofessional.