Interviewing developers

I've been interviewing candidates for junior/intermediate/senior positions all week.  I have some difficultly dealing with bad interviews. 

For instance, I just conducted an interview with a guy who supposedly has 20 years experience and a Masters of CS.  He didn't know what a hashtable was, or a linked list (said that was something to do with HTML and CSS), couldn't declare an array of 5 integers as part of a simple whiteboard exercise - I asked him to pass an array of 5 ints to a function that returns the numbers > 2.  He couldn't write a single line of code.  Apparently, he had even taught web programming with HTML and Javascript.

How do you end an interview politely, once you know that it's a waste of time to go further?

@Richard.Hein: The best thing is to structure the interview so you can have a brief chat about his experience, and whether you think he will fit, and let him have a test in the middle and a recap at the end. If he has failed, he is likely to tell you that it's not for him.

Interviewing is time consuming and patience testing, the best people can continue through a bad interview, and save the expletives and signs of irritation till after the candidate has left. To avoid this situation, try having a phone interview with weaker candidates prior, and then a formal one. You can tell straight away if the candidate is suitable.

I end by just telling them that I don't have any more questions for them and move straight to the end-game of the interview (e.g. "Are there any questions you'd like to ask about us?"). I don't believe in being unnecessarily rude to people so I just accelerate the end of the process.

Herbie

22 minutes ago, vesuvius wrote

*snip*

To avoid this situation, try having a phone interview with weaker candidates prior, and then a formal one. You can tell straight away if the candidate is suitable.

The phone interview is a good thing to do. In fact, you can do more than one. Keep them short so you aren't wasting time. One can be more general, "Tell me about yourself", and maybe some questions about their technical background. Another one can be more technical.

Phone interviews are less of an investment for both parties, and they are easier to wrap up with "We'll call you". Just make sure that they know what the goal of each call is so that you don't feel like you need to fill dead air. Making them fill dead air is a good thing though. That extra couple of seconds pause after they answer a question compels people to keep talking, and that's where you learn all kinds of fun stuff.

@Richard.Hein: Let the person know what your expectations are versus what they displayed for you.  This helps you move along and helps them prepare for the future.

Thanks for the advice, all.

My expectations were reasonably low for a senior dev.    Makes me upset I wasted 2 hours today on 2 very bad interviews.

@Richard.Hein: He had to have been lying about his experience and education. Any B.S. Comp Sci student could answer those questions fresh out of school.

51 seconds ago, spivonious wrote

@Richard.Hein: He had to have been lying about his experience and education. Any B.S. Comp Sci student could answer those questions fresh out of school.

Agreed. 

<rant>

This is literally what the first guy with 20 years total experience, 6 years on .NET wrote:

     x = new Array("1", "2", "3", "4", "5")

     for

Then sat there and stared at the board for a few minutes.

The second guy (after my original post I had another interview), with 15 years, 10 years on .NET:

PUBLIC INT[] Fn(INT NMBRS [])
{

     FOREACH

}

Then he said, "That's the best I can do, sorry ... I've done this a MILLION times ...."  Yeah, sure ... just nerves?  No problem drawing boxes and lines, but actual code ... froze up?  That's the excuse? .

The worst part is the second guy obviously knew a lot more concepts, and had a ton of BizTalk experience, understood at least what the GAC was and assembly versioning, what (some) of the CLR services are (GC, JIT compilation from IL), mentioned COM and vtables and how .NET improves on COM etc..., but couldn't finish the simplest coding exercise I could come up with that would allow some followup questions - such as, make the condition (y > 2) a parameter to the method (to demonstrate delegate/anonymous delegate/lambda expression knowledge (if any)), and I was hoping for someone that might try making an iterator and use yield return.

</rant>

Then he said, "That's the best I can do, sorry ... I've done this a MILLION times ...."  Yeah, sure ... just nerves?  No problem drawing boxes and lines, but actual code ... froze up?  That's the excuse? .

The worst part is the second guy obviously knew a lot more concepts, and had a ton of BizTalk experience, understood at least what the GAC was and assembly versioning, what (some) of the CLR services are (GC, JIT compilation from IL), mentioned COM and vtables and how .NET improves on COM etc..., but couldn't finish the simplest coding exercise I could come up with that would allow some followup questions - such as, make the condition (y > 2) a parameter to the method (to demonstrate delegate/anonymous delegate/lambda expression knowledge (if any)), and I was hoping for someone that might try making an iterator and use yield return.

He would've been a perfect candidate for a architect position HAHA...

Also, there's nothing wrong w/ ending an interview abruptly once you know it's not a good fit.

@Richard.Hein:

lol, that's horrible. I might cut the second guy some slack. It seems like he's been in management too long.

If you guys weren't in Canada, I'd send you my resume.

@spivonious:

In the U.S., we have offices in Bellevue (they are moving to Seattle soon), Portland, and Spokane.  In Canada, we have people in Toronto, Montreal and Ottawa.  We have people working remotely, from home, in New Mexico, New Jersey and probably other places as well, like Oslo, Norway.

Depending on how you structure your classes it's possible to take very little programming courses in a CS program (especially Masters which is close to 100% electives). But yeah they have to be lying about programming experience (or they were a "systems engineer" or "product owner", ie. never wrote code).

1 hour ago, spivonious wrote

@Richard.Hein: He had to have been lying about his experience and education. Any B.S. Comp Sci student could answer those questions fresh out of school.

And herein lies the lesson to be careful when dealing with "Masters" students. It's very, very easy to do a one year conversion course from an practically any subject and walk away with a masters, so it's always a good idea to find out what there undergraduate studies were in as well.

I honestly saw an entire lab full of Computing Science masters students, doing a conversion course, who were cutting and pasting numbers from an Excel worksheet into Calc, doing the calculations there, then pasting the results back into another cell. This was about a month away from graduation. I wept inside.

@AndyC:

@blowdart:  I think that I implied that with my body language, because at the end, the second guy was asking about whether there were any QA positions available. ... 

@Richard.Hein: Why don't you give them an assignment to do at home?

See how they code? Then depending on the job done, invite them over for a second interview?

LinkedLists are the ones with the bullets in HTML right?

@Richard.Hein:

This reminds me a lot of the popular FizzBuzz interview question. Just have them solve that over the phone or something.