My Interview Experience at Microsoft

My Interview Experience at Microsoft
Posted on August 10th, 2008 by Ben
(If the thought of reading more than 4,500 words makes you hyperventilate, please go instead to mysummary)
My Microsoft Background
Before I go into the specifics of the interview experience, I want to explain my background with Microsoft.
When I was just starting college, I got into an online community calledDevHood.It was a student-focused .Net community where you could sharetutorials, tips, code, and ask questions. Loosely associated with thiswere monthly .Net user group meetings on campus. My friend Ammon wasthe Microsoft student ambassador leading these meetings. By the timeI’d graduated I was one of the leaders on DevHood (I’ve since dropped afew places–the site is now mostly inactive), and a strong desire tosome day work for Microsoft was born. That desire has been occasionallyreinforced by various MS events that I’ve been to, people I’ve spokento, andblogsI’veread.
Around the time I graduated I made it into an “interview” situationwith Microsoft in the career center. I failed miserably. It was thefirst-ever interview I’d ever done with anybody, I didn’t prepare (atall), I was nervous (to the point of becoming very hot and sweating),and for some reason I thought I wanted to be a PM. Yeah….they nevercalled me back. But it was a learning experience.
My freshman year in college is also the year I moved from usingBorland C++ to using Visual C++ 6. I was also an early adopter of .Netand have generally been a fan of Microsoft. (You could maybecall me a fanboy, but I don’t think I’m completely one-sided. Iconsider myself pragmatic. Apple is just as good in many things asMicrosoft, but I am really annoyed at the press it gets and the Applefanboys. I think the biggest differences in OS X and Windows for most non-technical end-users are aesthetic.-Ed: please see clarifying comments below)
The effect of Google
I interviewed with Google last year, a processwhich I documented.Thank goodness–that experience really prepared me for this, thoughthere were some big differences. For one, I don’t think I wanted theGoogle job. It was fun, nice to do, gave me a good experience, but inhe end I wasn’t that disappointed. Microsoft was different. I wanted itand I prepared accordingly.
A month of e-mails and phone calls
It’s been a few months since this process started, so some of thedetails of timing or exact discussions may be off, but the overallstory is correct.
A few months ago, I was contacted by a staffing firm that worksdirectly with Microsoft to fill positions in various teams. I quicklyresponded, expressing my interest. The staffing agent who initiallycontacted me referred me to her boss, who was an extremely nice ladywho works out of her home. She did initial questions like what kinds ofthings I’m interested in, can I relocate, etc. Mostly, she told meabout the team that she is looking for:Live Search.She also acted as the buffer between me and Microsoft. She referred meto a Microsoft staffing person who also worked specifically with theLive Search group.
The Microsoft staffer talked to me first on the phone, about myprojects, goals, Microsoft, the Live Search team, and how interested Iwas. He then setup a phone screen with the development lead of the teamI was interviewing for, which was to take place about a week later.This phone call was postponed because of a meeting at Microsoft, and Iactually did it a few days later than planned. No big deal for me,though it was a little hectic because family was visiting and I didn’twant to discuss my interviewing with them at this point.
Phone Screen
I prepared for the phone screen by writing questions for theinterviewer, preparing standard HR-type questions and answers, andfiguring out what I wanted to say about myself (overall), my interests,projects, current job, why I want to leave, why I want to work forMicrosoft, and anything else I could think of. I also researched theteam a little (I didn’t know which specific team it would be at thispoint, so this was mostly learning the major components of the LiveSearch group). I did not practice writing much code at this point.
The actual phone screen was easier than I thought, up to the end. Westarted with a little chit-chat, then he asked me about my currentprojects atGeoEye. He did go intotechnical details, but not too much. He asked me about my opinion ontesting and other software engineering practices. I discussed unittesting and the efforts I had made to impose best practices in mycurrent team. I was pretty emphatic in my description of softwareengineering practices, since I had seen such dramatic benefits in mywork. We had a pretty good discussion about this sort of stuff and Ifelt like I was being taken seriously because of my experience. We alsotalked about working in teams.
After 30 minutes or so, he asked, almost apologetically, if I hadtime to do a coding exercise. Of course, I said yes. Oops. I didn’t doso well. With him on the phone, I e-mailed him my code at regularintervals. I took about an hour to hack out a recursive solution to aproblem which I had actually never solved before. I think I panickedand not having immediate feedback I went down the wrong path for awhile. I also should have thought of the design of the problem in termsof data structures, rather than just think of a vague code solution andgo for it. I learned a lot from this exercise.
Even with that, he said, “I’m going to recommend you come in for anin-person interview. The coding was a little weak, to be honest, but Ithink you have great potential.”
He also specifically recommended readingProgramming Pearlsby Jon Bentley. This book was onmy to-read list, so I gave it priority and ordered it, along withProgramming Interviews Exposed: Secrets to Landing Your Next Job.
Preparation
My preparation for this interview was intense. I went through as many problems as I could think of. With Programming Interviews Exposed,I read 2-3 chapters at a time, making sure I understood each problemand the answers thoroughly. Then I went back and solved each problem onpaper, without cheating and looking at the answers. Most problems Icould have done without reading the chapter beforehand, but a few werenew to me so the book helped a lot. It also helped show how manyproblems can be solved with creative application of basic CSprinciples. It also has good advice for handling salary negotiation andother non-technical aspects of the process.
Programming Pearls was even more helpful for formulating amental framework for solving problems. I cannot recommend it enough.The material is much more deep than Programming Interviews Exposedand it will force you to think a lot more. I read the entire book anddid as many problems in each chapter as I could. Most of them arethinking questions and not necessarily coding questions.
I also found and downloaded every list of programming questions I could find:
Sells brothers
A big list of good questions–I found some of the given answers could be wrong
Ace The Interview
I did problems almost every night until I started to feel burnedout. I solved every problem on those lists, other than some of thedatabase/hardware/irrelevant questions. Whatever you do, don’t give into temptation to look at the answers until you’re hurting with theeffort of solving them. Memorizing the answers isn’t enough–you reallydo need to understand them, whether you figure it out yourself or lookthem up.
On the plane trip out, I reread Programming Pearls and did the problems again, making sure I understood nuances that I hadn’t noticed the first time around.
The Trip
About a week after my phone screen, I was contacted by a travelspecialist who organized my trip. I was asked to provide some basicinformation, such as 5 dates when I could interview. I was nervousabout this since I didn’t really want to ask for more days off fromwork, but I just went ahead and hoped it worked out. Once the date wasestablished (nearly 3 weeks in the future), I was sent some documentson Microsoft’s online careers site. Logging in with my Live ID account,I filled out forms specifying my travel preferences, chose travel datesand times (I picked early the morning before, a Sunday, and to leavethe morning after the interview). I also chose a rental car since Ididn’t want to rely on a taxi. Microsoft makes all of the arrangementsfor you once you fill out this form.
On July 27, my wife took me to the airport for the direct flight toSeattle. It was a 5-hour trip, during which I re-read the entire Programming Pearls book.I had an aisle seat. At Seattle, I picked up the rental car fromAvis–an SUVish Ford. Redmond is about a 30 minute trip up the highwayand thankfully it was easy to get there. I hadprinted directions before I left home. I did drive right by thehotelwithout realizing it, and had to circle around–they’re a little backfrom the road, and the single sign was facing the opposite direction.
After I checked in, I went out almost immediately to find Microsoft. It was right across the street. I needed to findbuilding 19, which is about a 5 minute trip. I then went toAzteca, a Mexican restaurantnear the hotel.It was good food–too much, but very good. Microsoft pays for yourfood–keep your receipts. When I checked into the hotel, they told methat I could get any food from the little shop or order in andMicrosoft will pay for it. I didn’t make as much use of it as I couldhave. I didn’t want to binge on junk on the theory that a healthy bodyis a healthy mind.
After eating lunch, I went back to the hotel to study for the restof the afternoon. I went through the rest of the list of problems I hadprinted out. I was so exhausted by the evening, being 3 hours behind myhome time zone. I had some chips and juice for dinner, and went to bedat 8. I knew it was early, but I thought I could sleep for 12 hours.Nope. I woke up at 3:30 am the next morning. Oops.
I got up, read a bit, exercised until I was bored, took a long, longshower, ate a big breakfast, and reviewed a few other coding questions.At 9:15 I gave up and left the room. My appointment was with thestaffing representative at 10:00. I was there at 9:20. One thing Inoticed–lots and lots of diversity. People from all over the worldwalking around. I reviewed a few things some more and went intobuilding 19 at 9:40.
I got my name badge at reception and then sat down, eventually moving over to theMicrosoft Surfacethat they had set up. The Surface is an awesome piece of machinery.There are a number of demo apps which are a ton of fun to play with.There were games, a piano, and some graphical visualizations that allinteracted with multiple fingers at a time. They also have a number ofPCs and an X-Box360, which had a couple of people playing Rock Band onit.
A little after 10, my representative came out to meet me. He said heonly had 30 minutes to talk, but I think we talked for almost an hour.We discussed fairly typical HR-type things. He went over some numbersrelated to Microsoft, then leadership of the teams from Live Search ondown to the team I would be interviewing for. He discussed benefits,and then explained the day’s events. He gave me a piece of paper withan interview schedule that went through the 2-3pm slot. He said, “Ican’t tell you who comes after this. If you do well, the lastinterviewer will take you to the next person. If you don’t do so well,they’ll take you back here and we’ll talk about it.” Yikes.
When we were done, he escorted me outside to a waiting Prius, partof their shuttle fleet that anyone can use to go among the variousparts of the campus. I was headed tobuilding88.
The Day of Interviews
This is the part where I’m sure I’m going to disappoint some peoplebecause I’m not going to tell you the specific problems they asked me.I don’t think that’s fair, and there wouldn’t be much point anyway. Imay tell you a rough description just to give you an idea.
Each interview followed a similar pattern: discuss your work, tellme about [software engineering topic] and your experience with it, nowlet’s do a coding problem. Sometimes I did a problem quickly and theymade the problem more complicated, or gave me a completely separateone. I was not asked riddle-type questions. I was not asked dumb,typical HR-type questions (”What’s your biggest weakness?”).
Between every interview they will talk to each other and they willsend e-mails to the other people in the interview loop. Yes, they’retalking about you behind your back. And yes, they will tailor futurequestions to cover areas missed by previous interviewers, or to followup on a weakness. Also, not every interviewer is on the team you’reinterviewing for. I liked this because it gave me an opportunity tolearn more about other groups.
In the first interview, the coding problem was to generate awell-known data set. I first considered how to generate the nthiteration of the dataset, but she quickly steered me to solvingiterations 1-n (which is much easier). I went over the algorithm in myhead and out loud, before writing any code. Then I wrote the simplest,naive code that I could think of. I immediately saw some inefficienciesand worked to address them. She prodded me slightly to the answer shewas looking for (I would have gotten there).
The first interviewer was also my lunch escort. We went to acafeteria in a nearby building. I got a salad–not trusting my stomachfor too much more. The food is not free, but it seems pretty cheap(coming from DC). The drinks are free. I got water. During lunch, Ispent most of the time asking her questions about what she does,working at Microsoft, and the Redmond area.
After lunch, she took me back to the lobby to wait for the nextinterview. I took the opportunity to use the restroom and look at theart (there isoriginal art everywhere). I liked the boat made from junk.
The interview after lunch was with the same person who gave me thephone screen–the dev lead for the team. He asked me if I had looked atthe project they work on, and as soon as I said I had, he asked me whatI thought they could do better, or features to implement. I wasprepared with some intelligent things I noticed (which luckilycoincided with some of the things he had first noticed when he joinedthe team). We talked for a bit about software engineering, testing, andtask “chunk” size–i.e., how big of a task am I comfortable accepting ata time. This was an interesting topic which I hadn’t really consideredbefore, but after a little time understanding the question I used myexperience to give an honest answer.
He gave me two coding problems. Actually, before that he had askedme if I had ever done a certain problem and I answered that I had. Sohe gave me another one–a geometry/graphics-related question (not toodeep). I had seen the problem before when taking computer graphics incollege, and I knew the form of the answer. I just had to writespecific code. Then I had to explain as many test cases as I could forthe function. That problem didn’t take too long so he gave me another–afunction to score a round in a certain game (one that I hadn’t playedfor a long, long time). He explained the rules, I explained them backas I understood them, and then I verbally sketched an algorithm tosolve it. I wrote the naive code, fixed some algorithm mistakes andinefficiencies and I was done. I think I did well on this.
Then he took me to my next interview, which was the dreaded 2-3pmone. The same pattern ensued. This was a maze problem, and though Istruggled a little solving it, I had immediately known that depth-firstsearch was the way to tackle it, which was what he was looking for.
And…what happened next? Was I done? Do I get to continue until 5pm or am I done?
He took me to the next interview.
The next one might possibly have been my favorite. The guy I talked to had a lot ofpatent cubes,so I asked him about those and what his previous projects were. He thenasked me a very interesting conceptual/coding problem about how todesign a filter for the Live Search engine. We talked through it, and Icame to a decent solution, which I then had to code. Definitely themost interesting problem of the day.
Then on to the next…it’s 5pm now. They’re offering me food, but I’mpolitely declining because I just don’t eat in high stress situationslike this. That might be bad, but it worked for me.
A little bit of talk about software engineering practices, workingin a team, etc. Then he gave me an array-summation problem. I was veryfamiliar with this problem and explained that I knew a naive way, butthat it wouldn’t work in all cases (i.e., bad input). He asked me toexplain the problems, which I did. It was more like a discussion. Hethen gave me a tree-related problem, which I solved very quicklybecause I had practiced the exact problem before. Then he made itharder. He gave me a hint which at first confused me, but once Iunderstood what he meant, I grasped the solution.
It’s now 6pm. I was sure I’d be done. There are fewer people in the halls now. The day is over.
He takes me to the next interview.
This is with the boss. The dev lead’s boss. I’m unsure of his exacttitle, but he was in charge of the team I was interviewing for and oneother.
We talked for 45 minutes without a hint of coding. This was awide-ranging discussion about everything from MS benefits to housing totraffic to the future of the team, the impact of Yahoo, comparison toGoogle, and culture at Microsoft. I gained a lot of insight andappreciation for what they’re doing. At one point he started talkingsalaries and benefits, and I got extremely excited and I had to fightto keep a smile off my face (hey, I don’t want to look like a dork tooearly). I was thinking that they were definitely going to make me anoffer. Then he said other things which made me come back to reality.Finally, jokingly, almost reluctantly, he said he may be obligated togive me a coding problem, so let’s do a quick one.
Looking back, this should have been the easiest problem of the day,but I just got off track and missed the (now, painfully-) obvioussolution. It was a problem about finding the nearest object in ageographic region. I cringed when he suggested the golden hint to me,and my thought was DUH. Maybe it was too late and I was tired.
Finally, at about 7:30pm I was done. He called the shuttle dispatchand walked me out, where we chatted for a few minutes before I insistedhe didn’t have to wait with me.
Aftermath
I drove to the hotel and called my wife. I was elated. I knew I hadn’t been perfect, but I had just gone through a 9.5 hr interview. That couldn’t be bad. I thought for sure I was going to get an offer.
I ordered some Thai food from a delivery service, which I atestarting at 9pm. I watched a little TV, then went to sleep. I woke upat 4am the next morning to head to the airport for an early flighthome. It had been a very long day.
The next day I talked to the staffing guy (the one who had startedmy interview day) about the experience. He was very…confusing? not surehow to describe my interaction with him. He told me that they were veryhappy with me and I did very well, and yet some of the feedbackindicated slightly weaker coding than someone else they wereinterviewing. He needed to hear back from the team about the otherperson before a final decision was made.
Needless to say, this was not what I wanted to hear. I was prettyupset about it so my wife and I indulged in a little night out dinnerto assuage the disappointment. I was sure I was not going to get theoffer.
Two days later, I was at work when I got an e-mail from him. Theyare going to make me an offer! I quickly left the room (I share it witha co-worker) and called my wife. She was ecstatic. I was ecstatic. Iwas not expecting it, after the previous conversation. Looking back(and considering other conversations), I wonder if he was trying togauge my dedication and desire for the job. My other, more cynical,thought was that he was trying to prep me to take a lower salary or notnegotiate as hard because I must have “just squeaked by.” Maybe it’sjust to make victory all the more sweeter. Most likely he was on thelevel, but I do wonder… it just seemed odd.
That night when he called, I was feeling pretty miserable because Ithink I was food poisoned that day–I was feeling horrible–vision wasliterally shaking–very scary. But I kept it together and we talkedbenefits, salary, relocation, and the next steps. We did the“what-salary-do-you-want/what-is-your-offer” dance, which I lost ofcourse. Does anyone get an offer without stating theirexpectations first? In any case, the formal offer was worked out overthe next few days. I was on vacation in Utah when I got it (allelectronic). It was acceptable and I am now going to be a Microsoftemployee in September!
Random Thoughts
I’m going to go work on a team that is a direct competitor toGoogle, and they are a very significant challenge. Microsoft has a lotto do to catch up to Google, but there is something exhilarating aboutworking for the underdog. Even once the technology is better thanGoogle’s, there is significant mind share that needs to be won. We allhave our work cut out for us.
This is completely subjective and I’m biased, but I thought thepeople I interacted with at Microsoft were nicer than at Google. Maybeit’s because I did better, maybe it was my attitude, or maybe I waslucky with the people I spoke to.
When I drove up to the Microsoft campus the first day, it felt right.
There’s a lot to do in the next month–prepare the move, finish upstuff at work, prepare to buy a house, gear myself up for a difficult,demanding, but rewarding job–it will be a lot of work, but hopefullyfun at the same time.
Tips
My tips for theGoogle interview experience apply here. In addition:
Be enthusiastic. I got the distinct impression that they value this highly. Demonstrate it with your projects, your interests, your conversation, and even your tone of voice. That last is a hard one for me, especially over the phone. I’m enthusiastic, but I definitely have a hard time showing it verbally.
Practice, practice, practice. Spend a lot of time practicing with pen and paper. Write out every search algorithm by heart. About half the problems they asked me are in the two books I recommended above. But beware that they’re going to expect you to go beyond those problems. Consider these problems as refreshers in basic computer science, not a primer to help you get the job.
Know your computer science. If you don’t understand serious computer science, memorizing answers to lists of problems isn’t going to help you. Understand recursive and iterative solutions to common problems. Know data structures, big-O, and common algorithms. Know what methods and data structures can be used to solve which problems. You probably won’t be asked about advanced data structures or techniques–you just need to understand the basic ones really well.
Know the team. Research as much as you can. In my case, I knew what the project was and I could actually use it and come up with suggestions. This may not always be possible. If not, learn about the larger organization that you can get information for.
Have lots of intelligent questions. Many questions I asked to most people. Here is a sample: Favorite thing about working at Microsoft, Least favorite thing; My specific role. How big the team will be grown, impact of external events, comparison to competitors, strategy, where will the team be in the future, what’s your commute like, work-life balance, what do you work on (since not everybody you talk to is on the same project), what is your specific role, what other projects have you worked on at/outside of Microsoft, why did you move to this team, and lots more. The important thing is to be genuinely interested. If you are, then coming up with questions on the fly is easy, and you will have a natural discussion rather than reading a script. I moved from “script” to “natural” through the day as I became more comfortable.
You must know what you’re talking about. This allows you to have nice conversations instead of feeling like you’re being quizzed. You’ll feel more like a peer, and hopefully so will they. You’ll already belong. Also, you can’t fake this so don’t try.
The interviewers at Microsoft seemed much more willing to give me instant feedback than Google was. I could ask them what they thought of my code and they gave me honest feedback. I appreciated this.
The book I read on the way home wasThe Neutronium Alchemistby Peter F. Hamilton. It’s the sequel toThe Reality Dysfunction. Highly recommended for sci-fi fans.
Redmond, here I come.