I had a phone interview with HR which was very laid back and easy going. I followed up the next day and was told the CEOs would like to have a video interview. The following week I had the video interview which was more just to see if I'd be a good fit for the company. I was told the next steps would either be another video interview with some other leaders, or they'd just make a decision on the hire. After a week I followed up and failed to hear back. I then followed up again to get an update and failed to hear back for a second time.
It's highly unprofessional to ignore a candidates follow up email after going through the interview process and making it past the initial phone screening. The candidate gives up their time just as much as the hiring managers give up theirs. It's the right thing to do to follow up with the candidate to let them know of the outcome regardless if it's good news or not. Keep this in mind for future interviews.