The whole process took around 4 weeks. First, I got a phone call from one of the managers, who asked questions about my background, gave the details on the positions, and some machine learning / R questions. In a week I got a technical phone screening. The question was: "Given k sorted streams (k could be large), write an operator that accepts a list of the k streams and output stream o and outputs a single, fully sorted stream to o." I solved the problem and provided the O(knlogk) solution, but the person who interviewed me could not understand my solution (which was simple adaptation of merge sort). I spent most of the interview explaining the solution and complexity, but the interviewer was just ignoring my explanations (I suppose he had another optional solution and did not even try to think and follow what I was saying). She than asked me to code my version (I used Python because I only have 5 minutes left). Next day I got a call from a senior engineer who said that he had some questions about my solution. Instead he gave me a new problem on finding all the palindrome substrings in a string. I solved the problem efficiently and coded it within time limit, but interview said that they are looking for smbd who is more proficient (meaning it took too long for me to get the solution and code). I am very disappointed with the quality of the interviewing process at Vertica.
