I went through 3 technical rounds, each of them with 1+ hours duration, and did not receive an offer. There were two subsequent interviews that were booked then cancelled (super lengthy process). I interview people myself for my current company and know that one technical interview is more than enough to evaluate the professional skills of a candidate.
I honestly find disrespectful to submit people to so many steps, wasting their time and energy, mainly considering that their final feedback may be negative, as mine was.
Moreover, two of my technical assignments were performed in the same day. These interviews are super tiresome and certainly there was a negative reflection in my final results.
There was no guidance in what topics to prepare for, and during the test I was not allowed to use websites like stack overflow for reference. This does not reflect the daily reality of a software developer since we use those sources every day.
In my last interview I was asked about topics that aren't related to the area that I was applying for. I was clear that I work as a FrontEnd Dev, but they were specifically asking about software architecture topics, which I never worked with. Those skill requirements weren't written in the job description at all.