I had three interviews, one personal and two technical. The personal interview and the first technical one went very well - the interviewers were good guys, and they gave the agency positive feedback about me. The test was a simple search for substrings.
The third interview was a complete disaster. The interviewer was extremely rude and treated me with contempt the whole time - interrupting me every time I spoke - which made it impossible to "think out loud" on the test so he could see my thought process - talking over me very fast and talking down to me - explaining simple things as if I were a beginner. The test was just a simple unit test/mocking example, but I made almost no progress on it because the interviewer's behaviour was so distracting. Apparently the guy told the agency my tech skills were inadequate.
I didn't get an offer, and I wouldn't have wanted to work for that guy or for a company which employs people like him.