Microsoft interviews are strongly socialized - the process and (type of) questions are surprisingly uniform. Typically, there are 4-5 interviewers, plus the hiring manager, if you're considered a strong candidate. These group opinions are very powerful in the hiring process - it's extremely rare that a manager overrules the panel, even when privately, the manager may indicate that he or she would have hired the candidate based on their own read. (Bad hires eventually count against all the interviewers...)