Microsoft PhD Summer Intern Data Scientist Interview Experience — OA, Then Three Back-to-Back Rounds, Offer a Month Later

Timeline

• 10/13: HackerRank OA — one LeetCode problem and one data-processing problem
• 11/03: 3 rounds, back-to-back interviews
• 12/03: offer

Background: Statistics PhD, resume roughly 80% LLM-related research, no conference publications at the time of the interview (a few projects were finished and submitted), no industry experience.

Round 1: the interviewer was a senior guy. 30 minutes of behavioral questions plus 15 minutes of ML fundamentals. I walked through my resume and research projects, plus standard behavioral questions like conflicts with teammates. The fundamentals questions covered KNN and PCA — I hadn't prepared much for this part, so I was recalling things as I answered, but got most of it. No coding.

Round 2: 35 minutes of grilling on my resume projects plus 20 minutes of coding. My spoken English isn't great, and one project's setup was a bit convoluted, so explaining it was a struggle and took extra time. The coding question was to plot a precision-recall curve — I hadn't prepared for this at all, had to look up the definition of recall on the spot, and the interviewer gave a lot of hints. I stumbled through it and got it written.

Round 3: 15 minutes of grilling on my resume, then 15 minutes of rapid-fire LLM fundamentals questions. I'd prepared a lot for this part, so I answered quickly and don't think I got anything wrong. No coding. The interview ended up wrapping 15 minutes early, which made me a bit nervous, so I gritted my teeth and spent five minutes asking the interviewer about their day-to-day work before it ended.

Summary: most of the questions in every round came back to my resume, since all the behavioral questions eventually got pulled back to my research projects, and most of the interviewers' follow-ups were technical questions related to that. Microsoft not asking SQL or LeetCode was expected, but I was mediocre on questions outside my resume, especially some of the ML fundamentals. This was also my first time job hunting, so I was pretty nervous, and overall my interview performance was average. I got the offer a month after the interviews, purely out of luck.