All interviews lasted for 1 hour.
The 1st interview included soft skill and describe-yourself questions, as well as a quick leetcode-type question, which was fast & easy and had to be done on the spot while the interviewer was watching.
Interviewer was friendly, although admittedly seemed a bit inexperienced in the process.
The 2nd interview was conducted by a more senior employee and, similarly to the first interview, included describe-yourself and other basic soft questions (had to go through my background and previous job experience once more). On the technical side, the interview included an easy 'find what's wrong with this part of code' technical question, as well as (again) a brief coding exercise.
The 3rd interview was done by another senior employee, along with the CTO of the company. I was - for the third time - asked to describe my job history and was asked similar questions to the first 2 interviews. Then I was asked to do 2 easy (but a bit more difficult than before) leetcode coding tests on the spot, while the interviewers were watching.
Unfortunately, even though it seemed I did ok on the behavioral questions, I did poorly in the coding tests (solved them, but not with maintainable or elegant code) and received a letter of disqualification on the next business day.
My take on this whole process is that the first 2 interviews could have easily been merged into one. It was obvious that the only function they served was that of a buffer so that the 'precious' time of the CTO wasn't wasted on many interviews.
So basically instead of hiring a technical HR person to do this job, they decided that it was more efficient to give up the time of 2 engineers (a mid and a senior manager), only to have the CTO step in and take the decision.
In conclusion what I was lead to understand is that the upper management doesn't really value their employees' time and ultimately doesn't trust them to make a decision. Also they don't trust HR to conduct even a first-meeting interview (I believe they don't even have a proper HR department).