Same as someone already mentioned here, I also experienced the longest process I’ve ever had in my life. To me, it’s unreasonably long process managed by the hiring manager. I invested almost 3 months, spoke with many people in the team and got an update for onsite, but then suddenly the hiring manager decided to hold off the position later.
I applied online at the beginning of June, had a phone interview with recruiter. The 1st video interview with the hiring manager was cancelled in the last minute due to their meeting (although I was waiting in front of the computer in my house). The next day, I had the video interview with the hiring manager. Two weeks later, I had the 2nd video interview with the hiring manager again. Then about two weeks later, I had the 3rd video interview with another person.
After the video interview, I waited for a month for update, then again I spoke with three other people in the team via Google Hangouts (4th video interview). After the interview, recruiter told me I will have an onsite soon. A week later, the recruiter told me the hiring manger decided to hold off the hiring process for this position until Q1 (Jan 2019). They did not really want to hire someone for the role, and I feel like I wasted lots of my time and energy being invested for the past 3 months.
DO needs to take this issue seriously. The hiring manager needs to have a solid plan before the hiring process.