First round written: 30 questions in 40-50 min. Basic Java Related questions, hashmap, treeSet, loops questions. Second Round F2F: Project Description, Questions on Collections, how hashmap works internally, equals, hashCode method etc. Comaparable, Comparator, sort hashmap based on key value. Third Round F2F: Data Structure, time complexity, space complexity, merge sort workings and its time/space complexity.