Software Development Engineer II Interview Experience

I had to write my own conversion logic instead of using language helpers. The hard part was that the constraints and test cases were hidden, so I had to infer behavior from the examples. I remember reading the examples as if they were encoding the real requirement, and I believed the expected byte order was little-endian even though they never stated it directly.

Solve a graph problem around connected components using a union-set style approach and graph traversal.

I remember it being a connected-components style problem on an edge list. I think I had to return some kind of list of connected components, and to make it efficient I was thinking in terms of union set plus BFS or DFS. I do not remember the exact prompt, but that was the core of it.

I treated it as a pure motivation question about why I wanted to work there. It did not feel like they were pushing me toward one specific product or team. They mostly wanted to understand my interest in Microsoft itself.

I answered with a technical disagreement and explained how we worked through it and found a common solution. The focus was less on blame and more on how I handled the situation with the other person and got to a workable outcome together.

They gave me a very open prompt and did not add constraints, so I kept asking for direction. I ended up returning the length of the shortest root-to-leaf path. I was really reasoning through it logically more than naming textbook BFS or DFS, and they seemed fine with that. The interviewer mostly gave hints and sometimes said it did not matter as long as I could justify my choices.

I first tried to understand the problem because the prompt was very vague. We spent most of the time on the protocol and reliability side, especially how to send a very large update in multiple pieces. I discussed chunking the update, thought through TCP versus UDP, and proposed that the server first tell the car how many packages are coming so the car can count them and send back a warning if something is missing. We ran out of time before getting into security.

Given three C++ function headers, implement the underlying cache or buffer behavior they describe.

I only got the headers, so I had to ask questions to figure out what they actually wanted. The functions were roughly about writing bytes into a buffer, checking whether space was left, and reading data back. I suggested using an LRU-style structure for the implementation, and they seemed happy with that direction. After I coded it, there were no real follow-ups and we used the remaining time to talk about the team.