One round of written test, Two rounds of Technical interview, one round of HR interview. Written consist of objective questions of aptitude, C and basics of electronics. Technical rounds concentrate mostly on your past experience if it is relevant as embedded developer. Primary focus of first round was to know and understand in detail what I have worked in my previous job and my knowledge in that domain. Second round included all diffent concepts of C, solving few problems - pragmatically and analytically. HR round was fairly straight forward. All they want to know is weather you will stay here for long enough.