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On Guerrillas and Microsoft interviews

I am not gonna ask a "What will they ask me"? question.

But i have an interview with microsoft coming up and thought Joels website would be useful.  Well, it has made me thinking that getting to work for Billy Boy is a bit tough.

The Guerrilla Guide to Interviewing by Joel was useful. Unfortunately, it seems that Billy Boy does not listen to Joel. Most of microsoft questions that i found on the net seem to be of the "Aha" type questions. Brain teasers and maddening problems whch have little relevance to the real world. How the <<obscenity snipped>> should i know why a manhole is round?

Now, I am good at one thing and that is SQL. I cant answer anything on C and would not know how to get the number of petrol pumps in US (another brilliant microsoft question)

So if they ask me any of these, it means i should kiss the job goodbye. But what the heck !. I can always tell everyone that even Joel considers these questions as irrelevant. Maybe i will tell them on their face since i have nothing to lose .  Interesting to observe their reaction.

I do, based on my past experience think these questions are dumb. The "Brilliant" guys in my company were vastly outperformed by the "Not- So-Brilliant" guys because of one thing **some*** of the the brilliant guys lacked and no interview could measure - honesty and dedication.

I mean I would rather hire a guy who sticks with me and who does not know why a manhole is round rather than a guy knows and is always looking for the next big break in his career.

Wednesday, October 23, 2002


I cannot tell you how to pass one of the famed Microsoft interviews but I think that you pointed out something of interest that I can comment on:

>> The "Brilliant" guys in my company were vastly outperformed by the "Not-So-Brilliant" guys because of one thing **some*** of the the brilliant guys lacked and no interview could measure - honesty and dedication.

I had a number of friends at university who were at least 10 times smarter than me. They could do well on seemingly any course-work required of them -- except graduate with a B. A. Me, I just kept at it. I was stubborn, and though my grades weren't the best I graduated, which kinda counts in the end.

So if Microsoft doesn't want to hire you because you don't know why a "manhole is round" then I say, "f**k 'em." Be stubborn, it will make you successful, and get you where you want to be.

Chi Lambda
Wednesday, October 23, 2002

"Now, I am good at one thing and that is SQL. I cant answer anything on C and would not know how to get the number of petrol pumps in US (another brilliant microsoft question)"

Perhaps questions like this are intended to measure how your mind works rather than whether you can come up with some kind of "correct" answer or not.

If I were interviewing people for a job and you sat on your side of the table displaying the attitude you show here i wouldn't want you as a customer let alone an employee.

Robert Moir
Wednesday, October 23, 2002

I have had some really religious war-type debates with people about the whole issue of "Aha!" questions. My personal opinion is that the kind of people who like to ask "Aha" questions are the kind of person who take a lot of pride in their ability to solve riddles and puzzles and they believe that that is what makes them good developers.

I am not good at puzzles and yet I think I'm a pretty good developers. I routinely solve tough technical problems as part of my job and I also regularly troubleshoot client problems successfully. I consider my best developer skills to be stick-to-it-ivity and "gets things done" (the ability to really take responsibility for resolving a problem). Sometimes the problems I solve do have "aha" solutions, but then those typically occur to me because I really understand the domain well and I have solved similar problems before.

I like to ask prospective employees questions about a real problem we've had to solve in our products. I'll explain a portion of the domain to the interviewee and see what kind of questions they ask and whether they get interested or excited about the domain. Then I'll watch how they approach the problem and how many different possible solutions they can come up with. The best candidates can compare their proposed solutions with respect to trade-offs.

This can be time-consuming and it is an art to give the interviewer the right level of detail. I feel that this kind of question really gives you a good feel for how someone thinks and what they would be like to work with. Also, it gives them a chance to see what your company does and maybe they decide this is not the job for them.

Wednesday, October 23, 2002

I'm a senior manager at Microsoft that has hired many, many people.

I see and read *all* the feedback on all the interview candidates that go through my group.  Nobody ever asks an "aha" questions in my group, and I can't remember the last time I heard such a question asked in any group (I've been here ~12 years).

I drill into all my employees that they have to think of the hints they are going to give people.  If they can't give reasonable hints w/o giving away the answer, then it is an "aha" question and shouldn't be asked.  If they want to ask a question like this, it has to be a logic question (getting at how people think), not a puzzle.

If you wanted one peice of advice for your interview, I'd tell you to ask enough questions to make sure you know *exactly* what people are asking. I'm amazed at the number of people that jump right in answering a question before they actual have a clue about what is being asked.

If you wanted a second piece of advice, I'd tell you to think out loud.  I care almost as much about how you think vs what you are thinking.

Wednesday, October 23, 2002

I used to work at Microsoft and I interviewed engineers. I agree with Joe that "aha" questions are not as common as people think. Thinking out loud is almost more important than getting the correct answer. The interviewers want to gauge how you approach problems or what silly assumptions you make.

If you are interviewing for a SDE position, not knowing C is likely a kiss of death. If you are interviewing for web dev or SDET (test dev), then not knowing C is not a big deal. Since you say you know SQL, I guess you are interviewing for web dev work, so I wouldn't worry. Just don't try to hide what you don't know!

Zwarm Monkey
Wednesday, October 23, 2002

What's the deal for a Program Manager's positon?

Prakash S
Wednesday, October 23, 2002

The above Q was for Joe & Zwarm Monkey or anyone who has interviewd or worked at Microsoft.

Prakash S
Wednesday, October 23, 2002

Manholes are circular so that the manhole covers can't fall in.  If they were square, the distance between the middle of two opposite sides would be less than the distance across the diagonal, so you could drop it down the hole that way.

Keith Wright
Wednesday, October 23, 2002

Driving to an interview on a road with triangular manhole covers puts an odd spin on this question.

Wednesday, October 23, 2002

I've never gotten that question.  There are gazillions of reasons why a manhole should be round.  Transport, injuries caused by vertices, ease of putting the manhole in place, maybe area/perimeter ratios... many of which are more likely than the clever-sounding "so they don't fall in."  Anyone could give three good answers.

Wednesday, October 23, 2002

More discussion on manholes:

Steven E. Harris
Wednesday, October 23, 2002

For more info about interviewing at Microsoft:

Chris Tavares
Wednesday, October 23, 2002

As  a result of a previous similar discussion, I have performed an informal survey of the manholes in my area of North London (UK) and I can safely state that well over 90% of the manholes around here are square or rectangular.

Neil Butterworth
Wednesday, October 23, 2002

One reason for having round manholes is that the circular hole is stronger than a square one. The corners of a square hole are subject to much higher local metal stress, leading to fatigue and cracks.

Just Do It
Wednesday, October 23, 2002

Nashua New Hampshire has some triangular manhole covers.  An equilateral triangle with a lip can't be dropped back down the hole either.

Bruce Perry
Thursday, October 24, 2002

I went through two days of interviews at MS after graduating from college, and I was asked zero "aha!" questions. 

I was asked a different coding problem by every engineer I talked to (about 6 engineers in a day), and had to construct answers on whiteboards.  I had several data structure manipulation problems, one string-related problem. Some of them were "how would you write code to solve this problem....", some of them were "how would you organize this kind of data," etc. 

No brain teasers.  And at the end of the day, I felt like between those questions and a lot of talking about what I'd done and what I thought about their product (the team), my skills had been assessed.  For the record, it was the ONLY interview I've ever left where I felt like my skills were assessed in any way whatsoever.

former ms interviewee
Thursday, October 24, 2002

These are not "aha" questions. You can reason about these things.

Just me (Sir to you)
Thursday, October 24, 2002

Since manhole covers rest on lips I doubt a square one could fall in but I could be wrong. I always thought it was because:
A. Pipes are round
B. They weigh a friggin ton, so rolling them is a lot easier.

Besides, not all manhole covers are round and that would be the first thing I pointed out to the person asking the question.

Ian Stallings
Thursday, October 24, 2002

This is the key thing I wan't answered in any interview:
DOES THIS PERSON WANT TO SOLVE PROBLEMS, or have them solved for him?

i.e. if they have to learn a new API, or learn how to install/ configure an App Server, or if we as a team are having trouble with something new will they contribute to the problem solving process, or will they wait around saying I can't do anything till Dan solves this.

Daniel Shchyokin
Thursday, October 24, 2002

"Nashua New Hampshire has some triangular manhole covers.  An equilateral triangle with a lip can't be dropped back down the hole either."

Yes it can. Looking at the manhole, lift the cover and rotate it along its vertical axis 90 degrees, then pivot the cover at its apex, until it is aligned with one of the sides of the manhole. Plop.

Geoff Bennett
Thursday, October 24, 2002

Perhaps a more interesting question would be how to get the manhole cover through the hole. 

1.  Hit it with a large hammer (repeat until done)
2.  File one edge (repeat, brush off filings, put gloves on, until done, then Hit it with a large hammer, etc, etc.
3.  Find a bigger round hole (Search)
4.  Give it to someone else to do (Delegated operation)
5.  Do brass rubbing and send to city architect to reengineer size of hole. (Print and send back to client with a note saying 'How do I do this?')

Simon P. Lucy
Friday, October 25, 2002

> What's the deal for a Program Manager's positon?

Prakash, a Program Manager (PM) writes design specs, deal with customers, and give product demos. PMs tell developers what to create (in the specs), but they do not manage developers. They are peer positions in a separate job hierarchy. There are three job hierarchies in Microsoft's product groups: dev, QA/test, and program management.

PMs are often "creative types" who do not (necessarily) need to know how to code. Joel Spolsky was a PM, so most of the articles he writes on this web site are from a PM-perspective.  :-)

Zwarm Monkey
Friday, October 25, 2002

>>> Now, I am good at one thing and that is SQL. I cant answer anything on C and would not know how to get the number of petrol pumps in US (another brilliant microsoft question) <<<

I don't know what MS is looking for, but in the development work I do we have to solve problems all the time.  Sorry, Kart, but based on your statements here, I wouldn't hire you.

The manhole cover problem is about a 2 exclamation point problem and shouldn't be in an interview.  The number of gasoline/petrol pumps in the US is only a one exclamation point problem (i.e., no trick at all).  It should be possible to come up with an order of magnitude estimate using common knowledge.  It'd be a bit unfair to assume everyone has all of that "common knowledge", though.

Why do you have an interest in a job with MS? (Other than the obvious: in this economy any job is a good job).

Friday, October 25, 2002

re: manhole covers

I think it is a good question since there are so many aspects of its design and usability that can be discessed as well as the general benefit of seeing if the candidate has any interest in solving problems (Dan, you said it best.)

I have lots of experience with manhole covers since I used to travel through the sewers as a youth.

Square (more often rectangular) ones do fall in when you try to get them back on and it is a pain. Haven't seen the triangular ones. I can see they would be harder to let fall in but not that much harder. Also seems an unusual choice for ease of entry. (Where I do see square covers is in concrete septic tank lids and these are tapered along the thick sides, preventing them from being able to fall in.)

Round can be rolled as was mentioned, but here is kicker that all have missed -- it's much easier to set a round manhole back in place since it does NOT need to be oriented. Like the infinite mouse targets on the edges of the screen, you can slom these suckers right in by shoving them with your steel toed boots or whatever and they go right in. If tnhey are not juite in, a little push will make them go in. Nothing to it. Fool proof and fail safe. No more killing your partner when the manhole lid falls in and accidently bonks him on the head as he is coming out of the drain. No more smashing your fingers as you try to align the darn thing in two dimensions to get it to fit which is a huge hassle. Push it and it goes in. No thought. No skill. No mistakes. The ultimate in ease of use and simplicity. A huge advantage that you don't get when you are dealing with something with vertices that must be aligned.

I have never heard any one give this reason in an interview though I am sure it will get around now that I have revealed the secret. If someone did come up with an answer like I just gave, I would be very interested in looking at them closely as a candidate since it shows they may be sensitive to issues of good design. Round manhole covers are good design, optimal in every way. Square and triangular covers are bad design.

X. J. Scott
Friday, October 25, 2002

Hey!  I mentioned that: "ease of putting the manhole [cover] in place."  But I'm not saying this for vanity because I think it's more obvious than noticing the lid falling in...  Though you can construct a square manhole where the cover can't fall in, just like one where a perfectly-fitted circle does.

I'm thinking too much about this problem now that I no longer know what's obvious or hard...  and hearing "manhole" in my head so much is getting really disturbing.

Friday, October 25, 2002

There is an old story Kart, that obliquely explains why you are going to get asked questions about manhole covers and gas stations.

A hundred or so years ago in a far away country a  priest, a lawyer and an engineer had all been sentenced to death by public hanging.

First the priest came to the gallows, had the noose tightened around his neck, and the executioner pulled the lever to the trap. Nothing happened. The priest called out: "It is a sign from God! I am innocent and he has shown it". The prison governor reluctantly let him go free.

They fiddled about with the drop mechanism a bit, and then put the noose around the lawyer's head and pulled the lever. Again nothing happened. "Double jeopardy!" the lawyer claimed. "According to  subsection 3a of article 712 of the ....", but he didn't need to finish because the governor indiicated he should be let free.

Then the engineer came up to the gallows. The hangman put the noose around his neck and was about to pull the defective lever when the engineer called out, "Hang on ! I think I've worked out a solution to your problem!"

Stephen Jones
Saturday, October 26, 2002


Thanks for all your responses. I will keep in mind what joe said.

Saturday, October 26, 2002

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