Similar experience to the one other data science interview here except I am an experienced professional with over 10 years of experience and lived through enough technical interviews to know this one was extremely unprofessional. I found the interviewer to be extremely adversarial and hostile when/if they were paying attention to my answers. The interviewer would ask a question e.g explain how gradient descent works, I would answer e.g it is a method to find the derivative of the cost function; the interviewer would then say “you didn’t say the word derivative.” (This is verbatim). Other interactions included the interviewer criticising my explanation for a statistical learning method (which is fine) and went on to explain how I was confusing it with another method (which I was not). This is not a difference of opinion - this is the interviewer not knowing the difference between adaboost and gradient boosting and explaining one for the other. This pattern repeated a few times and initially I tried to cite sources or say something placating like “that’s not my understanding but you raise an interesting point and I’ll look into it”. As questions go, these are fairly standard for a data science interview but this interviewer seemed very invested in telling me everything I know is wrong. As the candidate, you can’t really start arguing with the interviewer, it is a lost cause at that point anyway. I chose to end the interview early since I have no intention of working with such hostile people. Oh and to top it all off, the interviewer’s phone starts ringing while I am in the middle of answering a question - maybe that’s why they were so distracted. Grub hub HR - Please tell your interviewers that candidates should come out of the interview feeling excited about the role and company even if it is a challenging interview process. As a customer facing company, you’re not just generating bad will with a candidate, you're also losing a customer.