total 3 to 4 rounds. The initial first round is with Talent Recruiter and expect this also asking technical questions, asked difference between ConcurrentHashMap and Map, which is more thread safe. which situation we should choose set vs list. What is time complexity for different basic data structure. How you go about designing the priceline like system, all these been asked in first Recruiter call. Then second round was with Principal software engineer, it is more like coding problem with real work style, there will be coderpad with imported Java project, having bunch of class, service and unit test already written. Some unit test is taking time and failing, looking the unit test, class, method, try to figure out why unit test search from Map is taking so much of time, what things you see wrong and how do you improve it ? It ends up being the Map the registration class hashCode method was overiden and it had bad code returning hascode of static string. What all other things are wrong in code, describe about project , something from resume etc