How do you measure an agent's quality?

"This was first technical round of interview, I went through typical System design videos but it needs in depth knowledge of system design rather knowing on high level. I kind of assumed it is going to be tough based on Linkedin profile of interviewer. He caught me off guard on few concepts. Interview can go in any direction so prepare deep on concepts. He asked me to write Pseudo code as well. AI Round was good where I was able to answer all questions."