I had an interview where the interviewers left too much space to allow me to ask questions and clarify but then didn't give clear direction to get the question answered. They then cut me off and said I reached no conclusion.

The second stage consists of several programming challenges (6 in total) - and 4 multiple choice questions. The questions require skills with file reading, input management and some systems level thinking, so Leetcode alone is insufficient. They warn you that some questions cannot be solved in your language of choice, but don't worry about learning a new language, those questions are more 'deciphering code' questions - you aren't really ever asked to code in a language that is not of your choosing.