Received a mail about 1 month after applying online to set up a phone interview.

The phone interview was pretty simple, and lasted for about 45 minutes. The interviewer just asked about my projects on my Resume.

I received a mail within 3 days saying that u cleared the phone interview and inviting my to the Redmond office for an onsite interview. However, the actual onsite interview took place only after 2 months because of the sheer number of candidates they were interviewing.

The onsite interview consisted of 3 rounds (including a lunch interview). They asked me about some design questions and some related to Trees and Lists.

Two days later, I received a mail from the recruiter that I didn't clear the interview.

Detail questions:
LCA of 2 nodes in a binary tree (not BST)
Rearrange digits of a number to find the largest possible number in O(n) time.
Write a CleanAPI() method to remove dirty values in a list of integers.
Many design questions.