Friday, October 23, 2009

Interview questions revisited

Ive been experimenting with webmaster tools and analytics for this blog, and while running a Google search , I came across (Hint use Google Cache to see the answers )
And on the BEA forums I see
Compared with my own

There's a pretty big difference between the kind of questions I ask and the kind of questions people seem to think will be asked or indeed do ask. A multiple choice question? really? I guess that was picked up from the BEA certification exam. (The less said about certification the better). Is there a point asking people something that's right there in the documentation or something that any respectable search engine could?
Lets get some assumptions out of the way
a. A bad resource is extremely detrimental to any software project. The contribution is negative and a big negative at that. It is better to not have the resource than have a bad resource.
b. There isn't an easy way to eliminate a bad resource at a short listing phase.
In most cases there are more people applying to the job than there are jobs. The resume is too abused to be an effective eliminator. If you look at a typical Java/EE resume , every specification in the EE umbrella is covered. Everyone has solid knowledge and expertise in all the specifications. On project experience is sometimes faked.
Would a quick multiple choice easily corrected paper help? I believe that this is actually bad. The people who aren't that knowledgeable know it, and spend their time memorizing documents/api's etc before an interview and can probably game this test. The people who I know are good in their fields usually don't have much time or patience for the minutiae, but are quite capable of doing this on demand. Project Experience would be a good indicator, but it is costly to verify this before hand. References are usually given by friends and aren't reliable. Typically a interviewee isn't going to provide a reference to someone who will give him a negative review.

So we can't rely on the short listing process to eliminate the bad apples. You must as an interviewer go to an interview thinking that you might be gamed. This means that straightforward questions might be answered by a bad candidate. This doesn't mean that you should ask the brain teaser sort of questions which only indicate that the interviewee is good at solving brain teasers (or has Googled the answers).

What then constitutes a good interview question?
Here are my criteria
a. The interviewee must be able to describe what he has worked on /is working on effectively. he must be confident in the modules he has worked. He must be able to answer questions related to his module when you vary some of the parameters. This is a deal breaker. A person who doesn't know what his project probably wont be able to handle yours either.
b. Most of the technical questions I ask are conversational and to which there probably isn't a right answer. The question is just the opening gambit, E4 for chess players. If I feel I am getting a recitation from documents , I introduce a twist or change a parameter of the problem (e.g. if the answer is something like I would design this with Spring by utilizing Dependency Injection IOC pattern and use the Hibernate ... - would be met with sorry the spring/hibernate license doesn't meet the project requirements, you can't use it).
c. Hands on experience on the technologies Im looking for is always a great plus, but it isn't a dealbreaker for me. If you can handle JSP, you can handle JSF. If you can handle Struts, you can handle other controller frameworks. What I can't stand is when someone states about all the stuff he has worked on at the start, how he was the heart and soul of the entire project, the life of the party, later changes his tune to say well I didn't really work much on that particular part. Thats a deal breaker. Dishonesty means I can't trust any of the other wonderful things you said, bye bye.
d. Never ask code questions without also providing the books, the documents, the search engine and a compiler. Writing code snippets on a whiteboard is stupid. Pseudo code questions are perfectly acceptable. Don't ask people to reinvent sorting algorithms when there are so many books (When will I ever buy that Donald Knuth book) that they could use. If you want to check analytical skills then use real life examples. There must have been numerous problems with your project, describe the circumstances and ask the resource to make suggestions.

In some ways I'm glad that I don't have to conduct interviews anymore. The last time I was proudly telling my mother of how many people I have rejected, she said why am I depriving people from working , and that you don't know how much they might need the job. While I still stand by my assumption that no resource is better than a bad one, it's still disturbing to think that I might(probably) have made errors in judgement and maybe just maybe I rejected a deserving candidate and maybe just maybe he really needed it. Like I said I'm glad I don't make hire decisions anymore

Throughout this post, I have referred to the interviewee as 'him'. Thats probably due to that fact that more than 90% of the candidates I've interviewed are male. Which is a sad state of affairs for software.

1 comment:

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