I've been both an interviewer and an interviewee and have been to some awful interviews and some excellent ones. And, because like all of you, I've been on at least one side of this arrangement I thought it might be useful to write a short paper on interviewing. This is also partly due to the recurrent theme appearing in the Code Project Lounge and the consistent distaste for the way that interviews appear to be conducted; usually by people wholly unqualified or prepared to do so.
Just as prospective employees will usually only get one shot at an interview the reverse is also true of a business looking for new talent. If you conduct a poor interview you may lose the prize catch.
Okay, I hear you say, interviewing is easy: you tell the candidate a bit about the job, ask a few vaguely pertinent questions, make one or two really difficult to make them squirm and then dismiss anything they ask or obfuscate because they've asked you a probing question. You don't think this doesn't happen? As a prospective employee I've been to more than my fair share of interviews and walked out on plenty when I realised that the person interviewing me hadn't got a clue or was telling me what he thought I wanted to hear or was just talking because he liked the sound of his own voice.
On the other hand, as an interviewer, you may wander in with a test in hand and ask them to complete it. It doesn't matter that the candidates will never be expected to know more than half the answers in relation to the job you expect them to do or could, in reality, read the book or Google the answer, you'll still fail them based on the result.
You may also trawl the internet for clever and obscure questions that appear to test the candidates' ability to solve problems under pressure but they're unlikely to face the pressure you put them under in the interview. Even working in the front office of a bank where the pressure is intense I've never been in a 'life and death' coding horror position: it just doesn't happen: whilst it may take no time at all to get something wrong you'll normally be given sufficient time to get it right, even if the user is screaming at you at the time.
So, first rule of interviewing: show the same respect to the candidate that you expect them to show to you or you'd want to be shown to you.
Second and most important rule: be prepared.
The First Rule: Respect
Very often interviews are conducted as if the candidate is a criminal whom you are trying to trip up with a loaded question. There is no purpose to this since the candidate is probably nervous anyway and is, undoubtedly, going to say at least one thing they'll regret once they've left the room, if not sooner. Why make it harder than it already is? The idea is to tease the best from the candidate, not the worst. Let's be honest, if a candidate is an inveterate or proficient liar the interview is not where you'll catch them out: you're just going to catch normal people making small mistakes. Just like you and I do. And you wouldn't want your career to hang on one small mistake, would you?
Show the candidate the same level of respect that you'd want to be shown. Be pleasant and courteous and make an effort to put the candidate at ease: that way you'll get far more out of the interview and you'll be able to make an informed decision rather an emotional one when it comes to making the final choice.
Of course one must take into account the business culture and whether or not the person sitting uncomfortably across from you can fit in and you should be able to determine that during the course of a well conducted interview and this should also form an important part of the decision making process.
Finally, remember that first impressions are important: just as you'd be aghast if a candidate walked in wearing shorts and a string-vest and had obvious BO think about the impression you're making on them. You are the front-line representative of your business. Think about how, if it was your own business, you'd want it to be represented. Even if I know the dress-code is casual I still wear a suit and clean shoes to an interview: if you know you are going to be interviewing look like you mean business, not like you're going to the beach.
The Second Rule: Be Prepared
Hand's up everyone who's been to an interview that was a struggle from start to finish and you left feeling that you'd wasted your time? I certainly have: I attended an interview recently and, apart from keeping me waiting for well over 10 minutes (I leave after 15 minutes if they haven't kept me informed as to why they're keeping me waiting) the 2 interviewers had no idea what the interview process should have been. They were disorganised and unprepared; asking me the same questions several times (not to trick me: they hadn't bothered writing down the answers and appeared more nervous than I was). They could not give me a clear answer as to what the scope of the job was going to be and could not answer other basic questions. After about 30 minutes I left and lodged a complaint with the agent that had got me the interview. It was a waste of my time and theirs. Net result: no one accomplished anything and they were no nearer to fulfilling the requirement.
As an aside it is entirely disrespectful to invite someone to an interview at a set time and then keep them waiting. If the interviewer hasn't got to you within 15 minutes you should leave: if this is how they treat you at the interview, what horrors can you expect if you do land the role? Conversely, if someone is that late attending an interview without a reasonable excuse you'll be questioning their competence and time-keeping before they've even had the interview.
Have an Agenda
An important part of the 2nd rule: have an agenda. This can be as simple as the three-step interview or as complicated as you like. The point is to have one and stick to it.
As an example the three-step interview is a very simple process to enable you to conduct an interview and is based on the old adage that applies to public speaking: "Tell 'em what you're going to tell 'em; tell 'em; tell 'em what you told 'em".
- Introduce yourself and anyone else in the room. Explain the purpose of the interview and how it will be conducted.
- Conduct the interview.
- Summarise the interview and explain what will happen next in terms of the hiring process. E.g.: We'll let you know by Friday.
Part 2 is the meat and potatoes of this process. You should have a list of questions that you wish to ask. Stick to these questions unless the interviewee says something to pull you wildly off course but be prepared to regain control and get back on track. It is your interview: you own it but always be ready to let the interviewee have their say and ask questions: this interview is very important to them or they wouldn't be there: give them a chance to speak and question you.
In fact you should invite the candidate to ask questions and be prepared to answer them honestly. There is nothing more de-motivating than taking a role partly predicated on what was said at an interview to discover it was no more than a half truth.
And there is nothing wrong in testing a candidate's ability as long as it's not just to satisfy yourself by asking questions that only you know the answer to or which are completely unrelated or irrelevant to the role being offered. No one likes a smart-arse.
In any case it is probably of far more use to ask the candidate to describe a specific project from their CV/Resume and ask about why they made the design or architectural choices that they did. What approaches do they take to problem solving, users or other developers within their team, etc.
And write down the answers they give. How can you expect to make a judgement when you rely purely on your memory of what may be a large number of interviews?
Of course, interviews can be longer and more complex than this and may span a number of meetings over several days. It may also be that you, as happens more frequently now, conduct an initial interview by phone. Whilst I understand that the sheer pressure of having to wade through a myriad of CVs and interviews can be a huge drain on time and resources, phone interviews can be misleading so should be used with caution.
In any case, observe the fundamentals and the interview process should be more rewarding and fruitful. Show respect for the interviewee and have an agenda. It acts as a roadmap through the interview and ensures that you don't waste their time or yours. It also shows that you're taking the process seriously and are a professional. Really, would you want to work for a business whose representatives come over as amateurs?