Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

How Effective are Technical Interviews?

jeanhsu.com

Post reply on HN
Print view View original

31–40 of 114 posts

Re: How Effective are Technical Interviews?

#31

Post by NickPollard »

tomh- wrote: post #18
jswinghammer wrote: post #12

Earlier quoted context omitted.

Implement: itoa

I don't know the answer of this question. I could do a guestimate on how such thing would work, but I've never coded c/c++ extensively. Am I useless now? I don't really see how this proves someone has basic knowledge about programming. However I could be wrong and this is a function that c/c++ programmers write on a daily base and is indeed a good indicator if someone ever ran a c++ compiler.

It's not in itself something a C programmer would ever really find themself doing, but as an algorithmic question it's fine - it's testing knowledge of looping, radices, strings etc. In C, you normally have to output the string in reverse and then reverse it, so you need to be aware of that. It's also a problem that's quite easy to explain (programmers are familiar with numbers and strings), but due to it's library availability, most people won't have actually written it themselves so it's not just a case of having done it before.

Coincidentally, I was asked this exact question in a phone interview this week. I didn't have to give exact code, I just walked through the principal of it (loop for each digit, dividing by the radix each time using the leftover specify the character (can be a lookup in an array), possible to use bit shifting in base 2/8/16 situations).

Re: How Effective are Technical Interviews?

#32

Post by pamelafox »

Four years ago, when I was interviewing for API Support Engineer in Developer Relations at Google, I was asked to complete a Technical Worksheet, with challenges like write an AJAX mashup, write an XML schema, write a letter to a disgruntled developer, explain HTTP verbs to a 5-year-old. It was basically a mini version of what I would later be doing on my job, it was really fun to do, and it was great preparation for the interview.

Unfortunately, as much as I loved that worksheet, I hear that we do not usually give it out anymore to new interviewees. I guess that it offends or intimidates people that are more experienced or interviewing at multiple companies. (I was a college student when I did it, and it did take me a few days of ignoring my homework to complete).

So now, we have to base our decision mostly on the technical interview, which as discussed, has its flaws - particularly if the candidate is a nervous interviewee. It does well at eliminating the folks we don't want, but I think a few times, it's eliminated people we would have benefited from. I think we'd do well by offering the worksheet as an option to all new interviewees, but not a requirement.

Re: How Effective are Technical Interviews?

#33

Post by ylem »

I think technical competence has to be part of it. If you know the person's references and those references are honest, you can ask them. But, I had one friend who had the fortune of always being surrounded by pretty bright, motivated, and competent people. For her first hire, she did a phone interview (international candidate), but was thinking more about issues like "does this guy seem like a good fit for the project in terms of interest" and only found out when he arrived that his technical expertise was far lower than what one would expect given his resume...

Re: How Effective are Technical Interviews?

#34

Post by tobych »

tomh- wrote: post #6

So I would be interested in knowing which companies have better, more successful alternatives to tech interviews. Is there any reasons why companies still insist that low level detailed knowledge of a language is a good indication that someone will do well on a job? I feel technical interviews are significantly harder than doing the actual job.

I thought that, too, after the recent interview I described in my comment on the OP. When did I ever need to think this hard? Um, when I was writing proofs in my Semantics of Programming Languages course at university, I guess. Most of my work days are spent pondering gently, with - a few times each year - a trip to the library to hunker down and really crunch some x's and y's. But it did make me wonder whether I wasn't choosing sufficiently challenging work, in the sense of the amount of raw "think, think, think" effort required.

Re: How Effective are Technical Interviews?

#35

Post by aplusbi »

sophacles wrote: post #25

I have found that for technical interviews, the following pattern works very well (hiring side): 0. Explain to the candidate this algorithm and why. It isn't magic, there are no right or wrong answers, just testing "fit". This is a case where foreknowledge does not change the outcome! 1. Get a basic grasp of technologies both interviewer and candidate have in common, via say, just chatting. This is vital -- find an a…

This sounds like a great idea but I feel it has a couple of short-comings. Most importantly is that it can be counter to the idea of preferring smart, motivated candidates over candidates that are well versed in certain technologies.

Additionally, this technique would probably work against college students and recent grads.

It can also be hard to quantify the results and the questions will vary wildly between candidates.

Of course none of those obstacles are insurmountable and I think that when this approach works, it probably works better than a more general tech interview.

Re: How Effective are Technical Interviews?

#36

Post by tastybites »

shortlived wrote: post #26
tastybites wrote: post #21

We hire people based on enthusiasm, general intelligence (you can usually tell after a few minutes) and a low level of demonstrated proficiency - we'll ask them to explain a code sample they wrote, or ask for a verbal description of how to solve a problem. We choose the person we like best, and if they don't work out after 2 weeks we fire them. Hot seat quizzing produces way too many false negatives. We are not googl…

Are there laws that allow/prevent the 2 week trial period for a business?

Not in California. It's called contract-to-hire usually.

Re: How Effective are Technical Interviews?

#37

Post by aplusbi »

eli wrote: post #23
tocomment wrote: post #4

I like interviews where you explain existing code you've written. I do well with those. I also do well if they give me a homework problem before the interview. True story. Interview at Google. They had me make this AJAX web application as homework before the interview. Three people told me they LOVED my solution and thought it was beautiful. I figured I was a shoe-in for the job at that point. But at the interview th…

I once tried giving out a homework problem to interviewees and a surprising number of people flat-out cheated! I absolutely hate "trivia" questions, but I feel like I have to ask people to actually write code during an interview even though it's unrealistic and a bit unfair. (I also think that if a candidate is flying to the interview, the employer should cover the airfare... but maybe that's why I don't get to hire…

I interviewed a candidate who had an impressive college project involving compilers on his resume. Almost any question I asked him about it was answered with "I don't know, the other guy did it." Even asking him "What did you work on?" resulted in an "I don't remember."

Re: How Effective are Technical Interviews?

#38

Post by alanthonyc »

patio11 wrote: post #20

I put tech interviews down fifty/fifty to "We don't know any better way of doing this" and "The unavoidable reality is that if a position is advertised openly then 98% of candidates are screamingly inappropriate for it and after applying a few filters to the resume we've gotten that to a more manageable 90% or so for interviews." Happily, there is a simple opt out mechanism. There are two ways to get into any company…

Great answer, as always.

However, it addresses the problem only from the point of view of the hiree. For companies looking to hire people, the typical interview process is equally a problem.

I think the "dating" process described by the OP sounds like a good solution for the hiring company. It's also a good signal to the employee that the company is serious about hiring the best, using the best methods.

Re: How Effective are Technical Interviews?

#39

Post by tptacek »

sophacles wrote: post #25

I have found that for technical interviews, the following pattern works very well (hiring side): 0. Explain to the candidate this algorithm and why. It isn't magic, there are no right or wrong answers, just testing "fit". This is a case where foreknowledge does not change the outcome! 1. Get a basic grasp of technologies both interviewer and candidate have in common, via say, just chatting. This is vital -- find an a…

I have over the last 8 years or so become terrified of interviewing techniques that revolve around having a conversation with a candidate, even (or, in fact especially) directed conversations.

Like many others before me, I've discovered that there is a huge gap between the ability to talk intelligently and productively about solving programming problems, and being able to actually solve programming problems. It's fine to hire someone who can reason through and discuss solutions... as long as you're also going to hire someone who will write the code for them.

Otherwise: get sample code, and watch them code something.

Re: How Effective are Technical Interviews?

#40

Post by aplusbi »

sown wrote: post #15

I have a sizable and growing portfolio of code I've written: some complicated algorithm stuff, some open source contributions; things like that. No one ever looks at it. I'm starting to wonder why linked lists are so important to employers.

I always look at that stuff and I ask about it during interviews, but I still ask general technical questions. Sometimes the candidate's contribution to a project is nothing more than writing the README file.
Post reply on HN