First, I had a phone interview with the recruiter about my latest side projects, previous job experience, and what are my interests in a position at Microsoft. At the end of the call, she told me to choose one date for the on-site interview.

I interviewed in Dublin, Ireland. They paid for the hotel and the transportation.

At the on-site, I had four interviews. The problems were easy-medium style, similar to those from LeetCode.

First interview: Twenty minutes talk about previous experience and side projects. I had the luck to be an intern before (two years before) in the same organization as my interviewer. One problem: Implement a function to simplify a Unix-based path.

Second interview: Five-minute talk about projects and one problem with a follow-up.

Third interview: Ten minutes talk about projects. Two problems, one with a follow-up.

Fourth interview: Ten minutes talk about projects and afterwards, a kind-of system design problem where we discussed how to implement the dynamic allocation of resources in Azure. This was related to what they are doing when you ask for four cores and if needed to scale at sixteen cores. How do you actually find those cores and map them to that client.

Implement a function to simplify a Unix-based path. Example: Input: /a/b/../c/. Output: /a/c.

Given a binary tree root and a function which prints the value of the node at the (x,y) position on the screen, write a function to print the entire tree on the screen. A lot of edge cases to take care of here...

1. The resolution of the screen (its dimensions).

2. Cannot collapse two values on the screen.

3. How do you take care of large numbers on the same vertical line?

4. This was the follow-up question. Maybe it was because I first started with using the same distance for all the children at the same level. The question was to optimize the distance used. For example, to use only distance 1 if I didn't need more. Some examples to understand what I'm talking about.

        1
   

d=1 / \ d = 1 2 3

                                1
                               / \
                             /      \
                            2       5
                          / \      / \
                         3  4 6   7

You cannot use d=1 at the first level because 4 and 6 will collide.

Implement a function to merge 2 sorted arrays into a third array. Follow-up: to do in-place considering one array can contain all the elements. Third problem was to reverse a linked list.

First problem I coded in Java; for the third, he wanted to use C/C++ (to see how I do with pointers).