In Initial level discussion, they will ask about you and your nature of work at the same time , they will explain about them and what they are expecting from you . In HackerRank Assignment, they will gave two problems which are related to stack and binary tree concept. It will be more tougher to crack the exams in stipulated time frame. Then they will share Mercury tour application, For that you have to create some sample cases and need to prepare the test automation scripts for those cases with proper framework structure. Then final 1:1 discussion related to manual testing and nature of the work.