Microsoft's hiring process is one of the more organized of the pack. However, it definitely helps if your case is being pushed by the hiring manager, so if you can, do maintain contact with them.

Interviews follow the typical structure for the industry:

1. Initial phone screen with the recruiter.
2. Phone tech screen with a member of the engineering team.
3. Follow-up call with the recruiter to identify groups you'd be interested in.
4. On-site, face-to-face interviews. Typically 4 (maybe 5 if you are doing a 'split' loop, or you're one of the more borderline cases).

Overall, the on-site interview experience has improved dramatically over the years for interviewees. Gone is the focus on brain teasers that left people numbed and shivering. It's more practical now.

This means a more mixed bag of candidates tends to get in, since it's not just about how smart you are. I have mixed feelings about how this evolved.

The questions are not that hard. There are definitely other tech companies that will challenge your brain much more.

Most of the questions seem to come from a standard set of about 150 questions that have been circulating for several years. Several books are published with these questions, so being familiar with them will give you a high probability of success.