Bloomberg Developer interview questions

First round interview was a 60 minute zoom call comprised of the first 15 minutes being behavioral and the last 45 minutes being a technical. On my technical, I received the balanced delimiters question (stack implementation). They really want you to focus on edge cases, I thought that the only delimiters were ( { [ but the interviewer wanted me to use a hashmap to store all possible theoretical "delimiters" which is where I messed up.