The difficulty of the coding/technical question(s) will depend on what position you are applying for and what round of interview it is. Overall, Microsoft asks very ambiguous questions to see what you will say. The first interview seemed much more qualifications based than behavioral based. Was 30 minutes long.

Three rounds of interview starting with phone screening, middle round of online interview and final round of three interviews all schedule within a couple weeks time. Interviews were Microsoft recruiters followed by employees