How to prepare for technical interviews

Interviewing well is integral to a successful career. Not only will impressing in interviews gain you more job offers, giving you a greater range of options to choose the best from, but being armed with the right questions to ask your interviewers will enable you to build a clearer picture of the companies you are interviewing with, and make a better-informed choice when deciding between offers.

A note: there are various points here where you’ll be advised to check details with “your recruiter.” This could refer to one of a wide range of people depending on the company you’re interviewing with and how you got in touch with them. It could be a recruitment co-ordinator, an engineering lead or the CTO. It could equally refer either to an internal recruiter at the company or an external agency recruiter, but in general terms it means the person who confirms the interview details to you. Unless you have specific advice otherwise, you should always view this person as your first port of call if you have any questions relating to the interview process.

General preparation

As well as the specific stage tips below, the following are basic elements of preparation for any interview stage:

Know the role and the company. If there are aspects of the company or the job that really turn you off or which you don’t think you can perform, it’s a waste of your time to go through the process. That said, don’t hold back on applying to jobs because you don’t tick each and every box on the job description. If you feel you could do the job with some learning and development, and everything else appeals, fire away.

If you’re not sure what the company does (“We craft next-generation solutions for businesses and consumers across multiple markets and verticals…”) dig deeper and find out. As long as you like the sound of the role and the company, and feel you could do the job barring a couple of skills to develop (which is generally a good thing), apply.

Know your interviewer(s). Once your interview is confirmed, look your interviewer(s) up on LinkedIn, and think about who they are and their role. Are they an HR person, or are they technical? How long have they been at the company? Where else have they worked? Do you have any mutual connections? If so, do you know any of these well enough to ask for advanced info on what to expect from them as an interviewer?

If your interviewers aren’t identified when the interview is confirmed, feel justified in politely asking who will be interviewing you. Your recruiter might not know the answer in 100% of cases, but they will usually be able to tell you and makes you look professional to ask.

The object of the exercise here isn’t to come into the interview with your interviewer’s life history memorised. Don’t get creepy about it, and don’t feel the need to show this research off. Just give yourself as much advanced knowledge as possible about the person you’re going to speak to, so that you feel as comfortable as possible during the interview and can make a sensible guess about what they’re going to want to talk to you about.

Prepare questions. Lack of curiosity can be a damning trait in interview processes. It can be mistaken for ambivalence, or intellectual laziness, and neither of these are impressions you want to give.

More to the point, you miss out on valuable information by not asking questions. Interview processes are two-way conversations that lead to both parties making a decision about whether they want to team up at the end of it. The more questions you ask, the more data points you have to inform that decision, especially if you’re offered multiple roles.

There’s no harm in repeating a few stock questions to everyone you meet through an interview process. It can be interesting to compare the answers different people, with different roles and perspectives within an organisation, give to the same question. That said, when doing your research into your interviewers, try to think of at least one unique viewpoint that each of them might be able to enlighten you on based on their role and their tenure.

Prepare your questions after you’ve researched the company and the role thoroughly, to avoid asking about things that are explained in easy-to-find places like on the website landing page. That said, don’t be too afraid about asking "stupid" questions here. No-one will expect you to have read every single blog post the company has ever published, and curiosity, on the whole, scores more points than learning everything online by rote. If you want to know something and a couple of hours or more’s research into the company hasn’t turned up the answer, by all means ask an interviewer who seems like they might know.

Screening call

Generally, if your CV is accurate and you’re genuinely into the company you’re interviewing with, this stage should go OK.

These calls tend to be a sense-check that the interview process is worth your time and that of the employer. You may well be asked to walk the interviewer through your CV and provide some added detail on the experiences contained within it. Any questions the interviewer has about your CV will likely be raised at this point, and it’s also common for general information like your salary expectations, notice period and right to work to be discussed.

You’ll probably be asked about your motivations, especially if this is stage is with an internal recruiter. The “Why do you want to work here?” question throws lots of people off, and it can appear multiple times and at various stages during interview processes. At this stage, though, especially if it is a recruiter rather than an engineering lead you’re talking to, it’s more likely to be geared more towards finding out why you’re interviewing in a general sense than specifically gauging your motivations to work at the interviewer’s company in particular. It will be more of a sense-check to ensure that the reasons you’re leaving your previous role can actually be addressed by the move. You might, for example, be using technology you hate at your current company, and if your interviewer knows they’re about to migrate across to the same thing, it’s best for everyone to nip things in the bud early on.

Be honest in your answers to questions like that, and others in this stage. It won't help you in the longer run to flood your diary with interviews for companies you're only lukewarm towards, or don't have many of the skills required.

Finally, bear in mind may well receive a “pitch” of some description at this stage. Whoever you’re speaking to will want to get you excited about the company and the role, in the hope that you’ll prioritise their interviews and tech tests over others that might soon come your way. Roll with this. Take notes as they speak - it looks great to be able to recall this stuff later in the conversation or the interview process - and ask follow-up questions on anything that piques your interest.

Technical screen

Similar to a screening call but with a more technical focus, and therefore more commonly carried out by an engineer or technical hiring manager.

This will cover your technical knowledge and experience at a high level. You’re unlikely to be asked to demonstrate any particular skills per se at this point, but you’ll be asked what you know and what you don’t.

As above, it benefits you as well as the interviewer to be honest here. Don’t assume you’ll be rejected for admitting you can’t do something. If it’s a skill you can learn on the job, the likelihood is it won’t rule you out. If it’s essential knowledge from day one, you’re better off without the stress of an interview process that will either expose this weakness, or worse, land you in a role you’re lacking essential skills for.

Expect some high-level questions about technical concepts, and be ready to have a discussion on the pros and cons of the technologies you’ve listed on your CV.

Technical interview

These tend to be an in-depth examination of your technical ability, and can take many different forms depending on the company. There is a spectrum ranging from a more in-depth version of a technical screen, where you and your interviewer will discuss technical concepts in detail, to much more involved processes involving white board diagrams, problem-solving challenges, system design tasks or live coding (sometimes in the form of pair programming).

As such it’s hard to give specific advice, so the best general pointer is to gather as much information ahead of the interview as possible. Your recruiter should confirm details of the format of the technical interview when booking it: if they don’t, ask them, and they will usually be happy to tell you.

As always, try your best to relax, enjoy the challenge, and treat it as an aspect of your work you’d enjoy. Ask questions as you go along as you would in a working environment: often the interviewers will be looking for evidence of your ability to work collaboratively as well as much as signs of your individual technical prowess. If you’re drawing something on a white board, make sure your explanations are clear, without going into unnecessary or patronising levels of detail.

Technical test

It’s not uncommon for companies to set a further, graded test of your technical ability beyond the qualitative information gained in a technical interview.

These can take several forms, including but not limited to:

• A timed technical exercise, completed either remotely online, or in-person at the company’s office.

• A larger “take-home” technical exercise. This could take several hours to complete, and as such would either have no time limit or allow a period of days or weeks in which it should be completed.

• A discussion of a previous project or code sample. Some hiring managers prefer to evaluate their interviewees’ code by reviewing a previous project the applicant has already completed and, sometimes, asking them questions about it. This has the advantage of saving time during the interview process, but can mean that different applicants aren’t compared objectively to one another.

In any of these cases, a subsequent interview either additional to or as part of a technical interview to discuss the technical test is not uncommon.

Cultural fit interview

These were once called “team fit” interviews but the term is becoming less fashionable, in part because it carries negative unconscious bias and, therefore, diversity implications. Detractors of rebranded “cultural fit” or "culture-add" interviews might justifiably argue the same thing.

On its own terms, however, a cultural fit interview is an assessment of how you will fit in with your colleagues on a personal level. This has implications not just for your morale and that of your colleagues in an outside-work sense, but more importantly impacts your ability to collaborate with them and strike up positive, productive professional relationships that help the team achieve its objectives.

Questions can therefore be wide-ranging. You might be asked to discuss your hobbies and interests outside work, your approach to interpersonal conflicts and resolutions (in and outside of work), your knowledge of certain working practices like Agile, or other subjects. You may also be asked some scenario-based questions aimed at assessing particular competencies, in a scaled-down version of a behavioural or values-based interview.

Behavioural / values-based interview

Sometimes additional to, sometimes part of, sometimes instead of the cultural fit interview is a behavioural or values-based interview that focuses on your ability to demonstrate particular sought-after traits or values.

Often, the questions will revolve around a particular scenario and your response to it. This could be by asking you about a past time you have displayed a value or trait (such as determination or teamwork), or asking how you might respond in a given situation.

Questions in these interviews will often correspond to a set of behaviours or values that the company identifies with, and in these cases they are normally published on the company’s careers page. It should be made clear if this is the case, in which case spend some time ahead of the interview reading through each and making notes on times you’ve demonstrated the behaviour in question.

If it’s not clear which traits are being examined, as always, ask your recruiter for more information.

Key Insights

• Start by reviewing the role and the company, as well as your interviewers

• Understand the focus of each stage of the process

• Feel free to ask a relevant person if you need or want more clarification