I went through 3 rounds. First round was kind of codility test, there are 2 questions to solve in some given time, I presented there the best solution as I have expertise in devising algorithms. Second round was telephonic, went for around 1.5 hours, there were 2 interviewers they asked me so many domain related questions as well as data structure questions and puzzles which were not very difficult to answer. Eg:1) How you will find a missing number from an array [0-99] having numbers ranging from [0-100] 2) How you will find out the middle element from an linked list. 3) Given an array of stock market data day wise, how you will find out out days on which you will get max profit on selling and buying stock. 4) Design patterns. 5) There is a long text file, how you will find out the count of all characters re-arranged in an ascending order. Then HR called me to meet for an F2F discussion. Things started going bad after this. I went to Pubmatic before 15 minutes of given time. HR attended me and let me to a discussion room with three chairs and a table. Two guys came in for interview, they were looking puzzled and not at all interested from beginning giving a feeling that they are doing other team member's work who is late to office. One of the guy was having less experience, I didn't understood how a guy having less experience can take interview of a person with 5 to 6 years of expertise. One can say that it will be learning for him, but then they should conduct mock interview for him. They asked me couple of question, the other interviewer asked me puzzles and data structure related questions and other domain related questions. They were more interested in puzzles and not at all in the software design and architecture, sometimes I felt that whatever stuff I was telling to them about design and algorithm is new to them. There was no professionalism as they were taking to each other in other native languages, one guy was repeatedly saying native language in between asking questions. The test is on problem solving and logical thinking but it requires time too. They were in hurry of getting in the answers and where not at all waiting while I was devising logic for the questions. I am sure that they could not have solved if I would have given to him in such a less time. Suddenly some other company guy came in between and told them that he has booked that room and the interview stopped and they left saying "ho gaya" to me and leaving resume there on table as it is, what a professionalism. I went out from that discussion room and no body was there to attend me, I sat on a cubicle near to me, then HR came say after 5 minutes and said that we cannot continue further as I was having good domain knowledge, problem solving skills, but data structure is average. I didn't got then what went wrong with data structure. When I was on the way to home I realized that they might me in hurry of taking Lunch as that was lunch time.. a waste of professional time of me and of Pubmatic. Data structure questions asked, 1) Given a matrix of say n*n each having an "led" at each unique element forming a filled back triangle, what data structure you will use to store/represent the data and algorithm to create a mirror image out of it. 2) Four dot triangle flip in minimum dot movement. 3) Sudoku. 4) Reverse number. 5) Sorting algorithm.