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Microsoft changed how it interviews software developers

businessinsider.fr

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Re: Microsoft changed how it interviews software developers

#171

Post by sprt »

JustSomeNobody wrote: post #14

> But the aha moment for me was that not everyone does well in those fast-paced brainstorming sessions. A lot of people (including me) prefer to sit with a cup of coffee and some data and try to think things through. This is me. Hard to get that across in an interview, but once people work with me, they're cool with me coming back an hour later in an email with some thoughts on the last meeting topic. They know and r…

Hijacking this thread to say that blog post isn't about Microsoft as a whole, but only about Microsoft's Developer Division (Visual Studio, etc.). The rest of Microsoft still uses the standard whiteboard/Leetcodey approach.

Re: Microsoft changed how it interviews software developers

#172

Post by vijucat »

grumpydba wrote: post #151
JustSomeNobody wrote: post #14

> But the aha moment for me was that not everyone does well in those fast-paced brainstorming sessions. A lot of people (including me) prefer to sit with a cup of coffee and some data and try to think things through. This is me. Hard to get that across in an interview, but once people work with me, they're cool with me coming back an hour later in an email with some thoughts on the last meeting topic. They know and r…

We french have an expression for that: "l'esprit de l'escalier", literally "staircase spirit". It's meant to characterize people who think about what they should have said/answered only when on their way out, in the staircases. I think I work this way. Maybe it's a way to ignore my lack of wit, my slow paced brain, and to maintain some self esteem.

Ha, wonderful expression, thanks.

Given that many people report that their best thinking is done while walking or taking a jog, it might not be too wild to try out interviews which allow the candidate to take a walk before they give an answer.

Re: Microsoft changed how it interviews software developers

#173

Post by psurge »

epicureanideal wrote: post #160
m0zg wrote: post #131

Earlier quoted context omitted.

It's neither. There's a DP solution for this problem and a recursive solution without memoization (with exponential complexity). The shortest solution I have seen was 18 lines of code.

Please show me a regex parser in 18 lines of code! Even 36! I did this exercise once and it took 100s of lines, I think using C++... but it's been a long time. Maybe it's significantly shorter in Python? But still 18 lines is impressive.

I probably screwed something up, but here's a 16 line attempt in Python, where the regex specials are limited to .?:

    def matches(pattern, s):
        if len(pattern) == 0:
            return True
        c = pattern[0]
        assert c not in ("*", "?")
        if len(pattern) > 1:
            if pattern[1] == "?":
                return (
                    len(s) > 0 and c in (".", s[0]) and matches(pattern[2:], s[1:])
                ) or matches(pattern[2:], s)
            elif pattern[1] == "*":
                for i, d in enumerate(s):
                    if c not in (".", d):
                        break
                return any(matches(pattern[2:], s[j:]) for j in range(i, -1, -1))
        return len(s) > 0 and c in (".", s[0])

Re: Microsoft changed how it interviews software developers

#174

Post by ams6110 »

YorkshireSeason wrote: post #136
Jach wrote: post #112

Earlier quoted context omitted.

Being on the technical interviewer side of the table it was a bit disconcerting to see people get to me who really should have been filtered out at an earlier stage. Still, for the type of lies that are most damaging, I still ask the question "what's the easiest way to uncover the lie?" Hence, FizzBuzz and FizzBuzz style questions work just fine if the lie is "can program". Why stress people out with trivia quizzes o…

too-strong fear of a lying false positive You might be a bit optimistic here: it's not always easy to deal with "lying false positives". Depending on the legislation it may be difficult to fire somebody, and involve going to court, sometimes going on over several years. Vindictive personalities may engage in sabotaging the company, the team, their (former) co-workers, as a retaliation for being fired. (Anecdote: I ha…

I don't think there's any state in the US where lying on your resume/CV is not legal grounds for immediate termination.

And any company that has thought about their hiring process for more than 30 minutes will have a probationary period of 30 or 60 days or so, after which employment can be terminated if the employee is not able to do the work.

Re: Microsoft changed how it interviews software developers

#175

Post by a-dub »

kronin wrote: post #148
dom96 wrote: post #147

Earlier quoted context omitted.

I have very little experience with interviewing candidates, but how can you be certain these people were liars? Maybe they simply were having a bad day, or got too much in their head with stress during the interview. There are many factors at play when it comes to a bad performance and it's not always simply that the engineer doesn't know the answer.

I give them a chance to judge their own skillset. After looking at their resume, I have an idea based on the projects they take credit for, what their experience level should be. If what they state lines up with their resume, and they are unable to answer a simple question, with multiple hints and help, then I absolutely assume they are a liar (edit: or delusional, which is even worse. An expectation I have of senior…

How do you know that you're not just crap at interviewing? Assuming people are lying is both extreme and presumptuous, no?

Also, are your people actually reversing strings by hand every day? I sure hope not!

Re: Microsoft changed how it interviews software developers

#176

Post by [deleted] »

kronin wrote: post #166
0x445442 wrote: post #163

Earlier quoted context omitted.

If you're interviewing for some core, low level algorithm development then fair enough but I suspect if that's the case you could come up with something a little closer to the real life domain. It's not that I think the question is too complicated, just not the best marker. In my mind, more relevant questions are ones that demonstrate real life experience in the field. For example, populating a tree of objects in a h…

I asked a candidate to implement an algorithm that reverses a string. I don't see that as a complicated problem. It's literally a for loop, and based on how they choose to implement it you can ask about implications of append vs. prepend, etc. I didn't ask them to implement dijkstra's algorithm, or even something as "hard" as breadth-first or depth-first search (which I feel any senior that deals with trees should be…

[deleted]

Re: Microsoft changed how it interviews software developers

#177

Post by baursak »

kronin wrote: post #152
0x445442 wrote: post #150

Earlier quoted context omitted.

> Couldn't code a simple reverse string algorithm You were interviewing senior engineers with Java experience and they couldn't come up with Assert.assertEquals("radar",StringUtils.reverse("radar")); I suspect you were actually looking for the implementation of StringUtils.reverse() and if that's the case then you were focused on the wrong skills.

It's the start of the coding interview. It moves on from there. This candidate didn't even ask if he could use Apache commons, and I hadn't yet specified that he couldn't use a 3rd party library. So yes. He failed on many counts. 1) not asking clarifying questions 2) not being familiar with some well-known libraries 3) not being able to implement a basic reverse string 4) not being able to explain whether or not a si…

How many times in your job did you have to implement reversing a string without calling a library?

Re: Microsoft changed how it interviews software developers

#178

Post by kronin »

a-dub wrote: post #175
kronin wrote: post #148

Earlier quoted context omitted.

I give them a chance to judge their own skillset. After looking at their resume, I have an idea based on the projects they take credit for, what their experience level should be. If what they state lines up with their resume, and they are unable to answer a simple question, with multiple hints and help, then I absolutely assume they are a liar (edit: or delusional, which is even worse. An expectation I have of senior…

How do you know that you're not just crap at interviewing? Assuming people are lying is both extreme and presumptuous, no? Also, are your people actually reversing strings by hand every day? I sure hope not!

Since you're attacking me, do you have any experience screening resumes? Phone screens? In-person interviews? Have you had the experience of a candidate that has apparently "done it all" on their resume, and confirmed their skill level when asked in-person, only to see them struggle with the simplest question in an area they deem themself an "expert" in?

I've interviewed well over 300 people, for positions from junior/entry-level to principal. If you read many of the comments to this article you'll hear other people with experience interviewing who also call out that candidates can and do lie. I don't like it, I'd rather it not be the case. I constrain the majority of my questioning to what a candidate claims to know on their resume. Here's a tip... If you don't know it (and I'm not talking about bullshit trivia questions), then don't put it on your resume.

Re: Microsoft changed how it interviews software developers

#179

Post by lilott8 »

hermitdev wrote: post #82
lilott8 wrote: post #43

Earlier quoted context omitted.

My life's motto is: "Let me think about it, I'll get back to you."

My goal when interviewing candidates is to ellicite this response at least once. I want someone who is honest that they don't know the answer and won't bullshit me about it. Also like to hear how the candidate would go about figuring it out, e.g. what resources they would use. I'm also fine with speculative answers as long as they're clearly stated as such, "I dont know, but I think it'd be something along these line…

Yeah, in an interview, I would certainly expand on that succinct motto; and attempt to do exactly this. But, as others have suggested, people respond too much instead of just thinking about a problem/issue/comment/etc. from all the angles (this skill was natural for me; but honed during the Ph.D. process.)

Re: Microsoft changed how it interviews software developers

#180

Post by m0zg »

psurge wrote: post #173
epicureanideal wrote: post #160

Earlier quoted context omitted.

Please show me a regex parser in 18 lines of code! Even 36! I did this exercise once and it took 100s of lines, I think using C++... but it's been a long time. Maybe it's significantly shorter in Python? But still 18 lines is impressive.

I probably screwed something up, but here's a 16 line attempt in Python, where the regex specials are limited to . ?: def matches(pattern, s): if len(pattern) == 0: return True c = pattern[0] assert c not in ("*", "?") if len(pattern) > 1: if pattern[1] == "?": return ( len(s) > 0 and c in (".", s[0]) and matches(pattern[2:], s[1:]) ) or matches(pattern[2:], s) elif pattern[1] == "*": for i, d in enumerate(s): if c n…

Pretty much something along these lines, except it's also required that both pattern and s end at the same time for a full match (this complicates the base case a tiny bit). The C/C++ solution looks more elegant because you can use pointers. Note that this particular version requires no prior knowledge of the algorithm and can be solved on the spot fairly easily.
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