How do you screen candidates?

Question

We have been interviewing for an entry level programmer for almost a year now. We just can't seem to find anyone that codes (and is entry level).

They all have nice resumes but when we bring them in for an interview we end up wasting our time and theirs. We have even recently moved to changing the interview format to quit the interview if they are clearly not qualified.

We want to implement a pre-screening process where we have them take questions online. (Even if 50% fully and completely cheat, we will have screened out half of the incompetent applicants.)

Our problem is that our HR department says that this is very unconventional and does not want us to do it. I need proof that this is a common practice (more than just an answer here that says "We do it", though that is welcome too).

Does anyone know any studies or sites that discuss this? I have seen the link on Coding Horror about this, and it seems like a good idea. But I need proof.

Anyone got any of that?

Answer 1

One of the main reasons for the existence of Brainbench (now Previsor) is to screen candidates prior to employment. According to an article on their site, 9 out of 10 organizations use some form of pre-employment assessment. Granted, there is probably a fair amount of marketing hype in the article, but I wouldn't call skills assessments "unconventional." Recruiters use them quite often, so I see no problem with HR departments using them also.

Of course, some candidates will claim they freeze when they take a test, so that also might be a consideration.

Answer 2

There have been a few places that gave me a "practicum" which was a simple coding problem to show my skills. This could be something to suggest as a way of screening out a bunch of candidates if you just want some basic coding skills.

Answer 3

Not quite the same thing but facebook certainly believe it can be useful (see the "solved and got hired" column):

http://www.facebook.com/careers/puzzles.php

on a wider note it might be best to get to the root of what their objection is - are they fundamentally against the unconventional or is it that they think it misses the key factors like interpersonal skills/has too much risk etc/ detracts their role in the process?

Answer 4

If you've been interviewing this long and haven't been able to find anyone suitable that's a bit of a red flag to me. That red flag is either for the geographical area you're in, or possibly in terms of your standards for selecting an entry level coder. Of course, I don't know your area specifically or your criteria so I apologize if that seems harsh.

It shouldn't be that hard to find someone entry level as piles of students graduate each and every year with C/S degrees and minimal work experience. We usually have a much harder time finding qualified and experienced developers. Implementing a phone screen will help immensely.

Anyhow my suggestions for the phone screen would be (since you'd prefer a C# skillset):

Ask some personality based open ended questions. These will help you determine if they're a possible personality fit before bringing them in. Open ended questions are surprising in that some candidates will completely sink themselves or shine brilliantly. Having loose boundaries on these facilitates ease of conversation and hopefully will allow you to see a bit more of the candidates for who they are and how they think.

Some examples:

• How would you approach building a software product?
• What do you think the single most important factor is to a projects overall success or failure?
• What does success mean to you?

Ask some basic object oriented design questions that are deeper than just definition based. Digging deeper (but not too deep) will prevent the candidates that have Google up on their laptop screen from breezing through. It's always better to get them to write code, but that's what can be handled in the in-person interview. Getting them to elaborate on basic concepts should be easy, even if they're fresh out of school. If they can't grasp the basics, you don't want them.

Some examples:

• What is polymorphism? Can you explain a working example?
• What is information hiding? When would you use it?

Hope this helps.

Answer 5

I did interviews for a small company for awhile, and now get to interview before someone joins my current team at work. Much like almost every tech company on the planet, we get resumes that aren't even close to qualified, and get resumes that are flat out lies. Spending my time - and other team members' time - interviewing someone is a cost, and if it costs us 1,000 hours to hire the best possible entry-level fit... there's a problem. To save ourselves time and heartache, we always do phone screenings first. I've never ever interviewed anywhere else that didn't phone screen first, either, with the one exception of being skipped past phone interviews by having a personal recommendation into the job.

For each job, we're looking at over a hundred resumes; if the posting is open long enough, many more than a hundred.

Forgive my bullet-point lists, but here goes.

1. Take a big stack of resumes, as many as 100.
2. Filter out at least nine out of ten.
3. Put at least eight into a stack to be called for a phone screening. If there aren't eight good ones, go through more resumes.
4. Call them, ask if now is a good time, or schedule a good time with them.
5. Ask them questions to confirm their resume is actually true.
   • Ask them about their current job or academic experience.
   • Ask them very simple technical questions.
6. Thank them for their time, and tell them to expect a followup via email in a week.
7. Hopefully have four good candidates. Schedule them in for an interview.

Again, if you're not doing technical phone screening, you should try that before going to anything more extreme.

Answer 6

Steve Yegge has an old blog post that was really good.

Five essential phone screen questions.

Answer 7

I found this one to be interesting since I am having a hard time getting my foot in the door for an entry level position, but other people are able to get an interview so easily. I think pre-screening is nice, but phone interviews in general is very difficult.

I find it hard to have a phone interview because I am so used to working with pencil and paper to scratch out my ideas before even implementing them on the computer. Even for the most basic concepts, I still have to spend some time to think about it before I can reply confidently. When I get a technical phone interview, I always feel pressed on time, so I want to give an answer right away without really thinking through the problem very carefully.

Other times, I am not sure if the interviewer wants either a naive or efficient solution to the problem. For example, implement Fibonacci number using recursion. Does the interviewer want simple recursion that calculates values that has already been calculated, or does the interviewer want a memory system to store values that were already calculated?

Answer 8

Read Johanna Rothman's blog. http://jrothman.com/blog/htp/

Buy her purple book. http://www.amazon.com/dp/0932633595/