Interviewing Do’s and Don’ts

This is off-topic and not really related to Agile, this is just an area of interest to me and I had a few ideas I felt I wanted to share. I originally started writing this post when I was interviewing others, but since then the role has been reversed and I have been looking at a new role for me, I have applied for and been interview for a couple of roles and about a month ago I started a new job. Consequently I have been reflecting on past interviews and so I thought I’d share some of my opinions on the topic. In doing so I am also challenging myself to see how much of my own advice I followed when roles were reversed.

This is written primarily from the perspective of me as interviewer, and I think this helps, if you can put yourself in that role of the interviewer it crystalizes what you would expect, allowing you to better prepare and chances are if you would expect it maybe your interviewer will too.

First impressions

The first thing an interviewer sees is your CV(resume), put in some effort to make it easy for them to read. As an interviewer I want the chronology to be clear, I want your core skills to be clear. Chances are the job advert was pretty clear about what I am looking for, if I don’t see it quickly your CV is heading for the reject pile. It is worth putting some effort into getting your CV in a clear readable state. I don’t expect anything fancy, but make it clear and readable, no obvious spelling mistakes. And if you claim a core skill, be sure that your job history supports it, claiming experience as a Programme Manager, or an Expert Nerf Herder, but having nothing in your past to support the claim will get you binned.

Be on time

I generally telephone screen first and I will endeavour to call you at the time specified. Be there! Be somewhere you can talk freely without distracting background noise, taking the call in the pub or on a train is not a good idea (I’ve had both). Not answering is a waste of my time, likely I will have booked a room, I’ll have done preparation and I will have been there early to be respectful and courteous to you. If you don’t answer and I have to rearrange, you will be playing catch-up, that is if I call you back at all. I look for team players and respect is a crucial element of that.

Similarly for the face to face interview, be on time. Not only is being late disrespectful, the inability to plan a journey for an important meeting reflects very badly on your ability to plan in the work environment. Communicate difficulties for the same reason, ability to communicate will be one of the key skills I am watching for.

What to wear

This generates a lot of discussion with quite a variety of opinions, I can only speak for myself and my opinion.  My former work place was fairly casual: jeans, T-shirts, and some dress more formally than others but it is not a formal work environment and only a handful wear ties regularly.  But when conducting an interview likely all of the interviewers will dress up, they will be in ties and suits and business attire or at the very least neat and tidy. Why? Because it is a sign of respect to the candidate interviewing. So when you show up to an interview we expect the same level of respect.

It gets more subtle here, and the rules are not hard and fast but there are a few tips that really should be observed. Unless it is clear otherwise, men should wear a suit, Navy or Charcoal are the safest, grey if you can carry it off.  Do not wear black, black says I only have one suit and I bought it for a funeral – get yourself an interview suit. White suits(not joking) or other colours are likely not going to work, it may work in some professions but in the land of the big corporations and the civil service it won’t do. And many SME’s are have inspiration to be bigger so assume similar attitudes.  Women have a little more flexibility, suits are good but anything conservative and smart works.

Software companies tend to be more relaxed, but even in those the hiring managers and HR are likely to still be a little old school, or as I said aspiring to be seen as established companies so if in doubt go conservative. (This is not universally true by any means and in the software industry there can be an almost a reverse snobbery, with ties being seen as a symbol of conformance. Suits are treated in the same way as ripped jeans and scruffy t-shirts are seen in a conservative organisation. Personally I find this sad, I believe you should be allowed to wear what you are comfortable in. Sadly you can be ostracised for non-conformance in either environment.)

Note:  For my last interview the interviewing company specifically said that the office was casual, and that I must not wear a suit.  The rule here is that you do what is asked, but even so you will still be judged on your appearance. I wore jeans and a casual sports jacket to reflect the culture but I still made an effort to be clean, tidy, and conservative in appearance, even when told to be casual it is better to be on the safe side.  It might well be that you can wear shorts and flip flops when you start work, but the interview, like it or not, is about assessing you and so smarter is better.

Attention to detail

It is not enough just to wear a suit, it needs to fit properly, you need to look smart, cut your hair, wear a suitably matching tie (also conservative) and learn to tie it properly (People that know how will notice). Wear smart clean polished shoes either brown or black, and again people will notice. If your shoes look tatty it shows a lack of attention to detail.  Some of these rules can be broken if you do it right, I recently had someone interview in a light grey suit with no tie, but he was smart well-groomed and confident, he looked 100 times smarter than the guy before him who had an ill fitting suit and poorly tied tie.

Someone asked me recently whether a waistcoat was appropriate for an interview, my response is that they will stand out, in the same way as not wearing a tie, if they look comfortable and confident and it matches their demeanour then it will likely be okay but it could easily come over as trying too hard or worse the only thing people remember. My advice would be to remain conservative and don’t wear anything showy or save it for a second interview. Unless it is for a role where that would fit in.

Again in the casual environment, you should make an effort to wear your outfit appropriately, and it is still important to be clean tidy and well-presented. Causal does not mean you don’t have to make an effort.

The Greeting

Whether on the phone or in person, greet with a smile and a clear friendly introduction. If in person shake the hand of everyone in the room if possible. If on the phone make a note of everyone’s names. If your name is difficult to pronounce say it clearly, and if you can do it without looking odd repeat everyone’s name that you are introduced to, it will help you remember and ensure you get the pronunciation right upfront.

I’m sure by now you are thinking that everything I have said is about appearance and not substance, and you are quite right, and that is because a lot of candidates are mentally rejected before we even get to the first question. A scruffy looking candidate that turns up late and cannot communicate a clear greeting is not going to fit in to any team I want to be a part of, no matter how technically capable they are. Communication and respect are the two qualities I value most and I will have a pretty good idea of those before you even sit down.

I will try very hard to reserve judgement and to impartially assess the answers to your questions, but the reality is that if you have messed up the first impression it will be hard to recover. 

Please don’t bluff

No really, please don’t bluff. If you say on your CV that you are a Scrum Master be sure you can back it up, leading a Daily Scrum when the Scrum Master was off for a day does not make you a Scrum Master.  Same goes for technical skills, you are not skilled in C# if you worked in the same company as someone that wrote C#.  I know listing lots of skills gets you interviews, but if you can’t back it up you are wasting my time and yours, you will be rejected. If I sense you are bluffing in one area I will assume you are overstating in others.  Tell me that you are a competent C# developer and although you haven’t done MVC you have every confidence you could, then I’m inclined to agree with you, but bluff and I’ll assume the worst.

Don’t be afraid to say “I don’t know”

I ask about a lot of skills and experience, I am interested in your exposure to pair programming, TDD, BDD, cross-functional teams, experience with Agile, not to mention various more technical questions. But you don’t need to know the answer to all, no one knows everything and one of the things I am looking for is how you handle your limits.  I had a recent interview where I asked those questions on a telephone interview and the candidate wasn’t aware of BDD (Behaviour Driven Development) he said so and asked a couple of questions about it. By the time of the face to face interview he had done some research and done a Pluralsite course on Specflow and Selenium and talked quite animatedly about the subject, his initiative was of far more interest to me than him not knowing an answer. He was the only one of 35 candidates hired.

Nobody knows everything, it is important to be aware of your limits and how you push them. Again another candidate was asked a fairly tricky situational question, he didn’t know how to answer it immediately and asked for a moment or two to think about it, he was polite and we moved on, a few minutes later he brought the conversation back round, said he had thought it through and gave a very good well considered answer.

My assumption is that you can learn what you don’t know, but you can ONLY learn if you first acknowledge that you don’t know it.  Someone that bluffs and I see it will be marked far far lower than someone who is aware of their limits. 

Are you smarter than me?

I generally hire a lot of contractors so I am expecting a pretty high standard of candidates, as with any form of assessment or estimation it is very difficult to be absolute or objective, so my measure is me. I find it far easier to judge someone by a relative comparison to myself and my abilities than it is to an absolute scale. My general rule of thumb for technical roles is that if I think they could do the job better than me then I am satisfied and will invite them to a face-to-face interview where this interview becomes an assessment by multiple people including technical experts and some canned questions and tests. But I strive to be picky, I’d rather filter too many than have a team suffer from a mistake. Conversely I expect the same when I am interviewed, I expect the bar to be high and have to prove myself.

When interviewing less experienced candidates I am looking for an aptitude to learn rather than learned knowledge, I am far more interested in your willingness to adapt, than in how much you know. Be prepared to talk about how you learn new things, how you stay fresh.

Ask questions

This is crucial, it may be an odd thing to say but I can learn more from the questions you ask than from your answers to my questions. Come prepared with a number of questions to ask, some about the company specifically, so you can show your interest in this role specifically, but for the others make them questions that you are genuinely interested in discussing. If you can demonstrate passion and enthusiasm about a topic that is likely to be common ground with the interviewer. A new tool or technology or aspect of the role something that may open a discussion.

I am mixing context a little here, but when I look for a role I am aware that most people – including me – are driven by three things: Autonomy, Mastery and Purpose. If the description and questions from the interviewer didn’t make these goals clear for the culture of the organisation then ask questions that would clarify this, I am speaking for me now rather than generically but this is now a crucial requirement for me. See more on this –  Dan Pink – Motivation

Ask the right questions

By this I mean don’t ask the wrong questions. An interview is not the place to ask about benefits or perks or working hours, and not salary. If the interviewer mentions these make notes but don’t ask about them. You can ask these questions later. A candidate that asks about working from home, or flexi hours may give the impression that these are crucial factors to them and may raise concerns about focus, motives and dedication. Even if unfounded it is better not to give the wrong impression.


Ask yourself, over and over again. “Do I really want THIS job”  it can be very easy to be so excited about getting an offer that you get wrapped up in the enthusiasm that they want you, that you forget to ask – do I want them?

This new job could well be your day to day existence for the foreseeable future, do you really see yourself happy in this role. Consider all eventualities and try to be objective, sleep on it. It is not the only job out there.  Just because they have offered doesn’t mean you have to accept.

This is especially true if you have oversold yourself or bluffed, getting the offer is a success but when you start work you have to deliver.

This is now the time where you ask about benefits and working arrangements. If you are uncomfortable with the salary offer say so, once you are in the role it will be far harder to negotiate.

A lot of what I have said here is my opinion and is subjective, and no doubt there are many different opinions out there. But this advice has served me well both as an interviewer and an interviewee. As with any topic like this I am delighted when I get chance to debate it and be challenged with new ideas, none of the advice should be considered fixed or universally true. 

The most important advice though is that you should make sure the job is what you really want.  When you are happy in your work and fulfilled everything else becomes easier.  Whether you are an interviewer or an interviewee – Please watch the Dan Pink video it may make you rethink how you perceive your own or your team’s motivations.

Typical interview styles

The interview itself.

What I have observed is that interviewing is generally composed of one or more of a very small number of techniques:

  1.  Free-form, gut-feel unstructured or semi-structured chat and questions between candidate and hiring manager.

  2.  More formal pre-defined questions structured and consistently asked to all candidates.

  3.  Some variety of standardised test, essentially IQ based.

  4.  Questions posed by a technical expert with a desire to highlight his superiority rather than assess your capability.

  5.  A technical test or series of technical questions intended to be pragmatic and fair.

  6.  Aggressive panel questioning

  7.  Psychometric testing: verbal/numeric/diagrammatic reasoning or personality tests.

  8.  Presentation by interviewer on why the candidate should work for you.

There are studies and statistics that rank the effectiveness of the different techniques for selecting good candidates, I won’t pour them out here – I am not an expert and I’d just embarrass myself. But in my experience 1 is the most common, often combined with 4 or 5. But logic states that 4 is a waste of time and puts off candidates, and studies show that 1 and 5 are actually very, very poor indicators of ability and capability for the role and do not result in long-term success.

So what works? 

2, 3 and 7 are by far a better method of assessing candidates, followed by an independent panel-decision based on the documented evidence taken from the interviews – the interviewer should not be allowed to make the decision independently as they display bias (subconscious or otherwise).

But 2, 3 and 7 are hard, it requires yet more work on what is already a tough and time-consuming process, so very rarely gets done.

The reciprocal nature of an interview (8) is so often overlooked, if you want the best people and you want to get the best out of them, then not only do you need to decide if they are right for you, you need to convince them that your business/team is right for them. You should be putting as much effort in to impressing candidates as they put into impressing you. You are competing for them in a buoyant market.


Doing it right.

As an interviewer, my best experience has been for a company that did a combination of 2, 3, 7 and 5. We put a lot of effort into interviewing, but the majority of people still failed the combination of tests, especially the technical test. The test felt ‘easy’ to us and some candidates did well, but the results didn’t match the apparent skills of candidates, in hindsight I think it confused the process. The problem is that technical tests are not effective at assessing ability during an interview, there are simply so many other factors at play.

Relying on structured questions, IQ tests and psychometric tests may feel clinical and impersonal, but very likely the best way to find the right candidate. But ego plays a role and when hiring for a team, we are only human and so many hiring managers want to rely on their own instinct, even if evidence demonstrates this is unreliable, so it is hardly a surprise that many hiring managers favour their instinct over a structured process.