How to Prepare for a Coding Interview

If you’re pursuing a career as a developer, then at some stage you will want to know how to prepare for a coding interview. Here at Coder Academy, we see a lot of students who have a wealth of life and work experience, but when it comes to coding, they’re relative newbies. This article will be particularly useful for career changers and emerging tech talent, but also offers advice for anyone seeking a role in tech.

To make sure we’re offering tips from someone in the know, we’ve taken some advice from Katie Wilson, early careers specialist at Mantel Group. Katie recently gave a talk for Coder Academy students and offered actionable advice as well as coding challenge examples used by Mantel Group.

Mantel Group is a Coder Academy industry partner and includes eight tech-focused businesses under its umbrella. Their focus on fostering emerging talent has helped them to refine their traineeship, mentoring and hiring programs, and makes Katie a great person to go to for advice.

How to Prepare for Different Styles of Coding Interview

There are a number of ways you may be asked to interview for a position. Informal or formal phone interviews, in-person interviews and video interviews are all common. Then there’s the tech interview – this one is often dreaded by new and experienced coders alike – the interview where you must show your coding prowess live.

Katie stresses that it’s important to look at “all aspects of interviews, because I know the technical interview is probably the most scary one and the one that everyone kind of thinks of as the most important one during the interview process, but actually, I think every stage of the process is as important.”

How to Prepare for a Phone Interview

Depending on the organisation, Katie says, you may be expected to take part in a scheduled or unscheduled phone interview. An unscheduled interview may be a fairly informal call letting you know that you’re through to the next interview stage. A scheduled phone interview may be more formal and be used to screen candidates before the next round of interviews take place.

When the phone call comes unexpectedly, Katie says that applicants shouldn’t feel afraid to reschedule the call at a time that is more convenient, and to take their time to prepare. If you have applied for multiple positions and you can’t recall in the moment everything that you need to about the company and the role, then you are doing no one any favours by bluffing your way through the phone call.

“This is really to understand your motivations, what have you been studying, and really, is our program what you’re looking for, and fit for purpose in terms of where you want to start your career,” Katie says.

So that both you and your interviewer can get the most out of any scheduled or unscheduled phone calls, make sure that you keep track of the positions that you have applied for in a spreadsheet or other convenient format. Prepare questions to ask during interviews, and make sure you’ve researched each company so that you can show genuine interest.

How to Prepare for a Video Interview

Usually, video interviews are only used by larger companies when they are running bulk recruitment. If you are asked to complete a video interview then preparation will be crucial. You will likely be given a set amount of time for each answer, so make sure you know what you want to say, and practice keeping your answers succinct.

Test your internet connection, audio and visual set-up and practice looking directly at the camera.

How to Prepare for In-Person or Virtual Interviews

Face-to-face interviews are just as likely to take place online these days as they are in-person. Either way, your preparation will be fairly similar. Find out beforehand what type of interview this is – are your interviewers looking at this from a cultural, behavioural or technical standpoint, or, most commonly, a combination of all three.

Having the right tech skills will always be important, but Katie says that for junior developers especially, these may be second in importance to other skills. What she is most commonly looking for at Mantel Group is applicants who will be able to grow into their role – people who are passionate, keen to learn and who fit the company culture.

“When we talk about human skills, that’s what is usually referred to as soft skills. So, what kind of transferable skills you have from a previous career, if you’re a career transitioner, what sort of skills you’ve learnt from jobs you’ve worked while you’ve been at uni or at school, or something like that, that can help with the different elements of the role that aren’t technical,” Katie says.

Remember that the interview also offers you a chance to work out if your values and goals are aligned to the company’s. Ask questions, not just with the aim of impressing your interviewer, but with the goal of working out if the role you have applied for really is right for you.

Talk about the company in your interview. Make sure you’ve done your research, as Katie says it’s surprising how many people get to interview stage without knowing much about the company.

When your interviewer asks you to give examples of your past work and achievements, make sure you give real-life examples. They don’t have to be from a tech-related role, as long as they give the interviewer the information that they need. It’s important to recognise the transferable skills that your potential employer could value.

It’s also a good idea to structure your responses using the STAR method.

Situation – Talk about the circumstances in which the task was performed.

Task – Detail the task and what it involved.

Action – Tell the interviewer what actions you took specifically, not just what your team or organisation did.

Result – Make sure you talk about the real outcomes. Things don’t always have to have gone to plan – you can still explain what you’ve learnt from “failed” projects.

In the early stages of your career (or career change) Katie says it’s also perfectly reasonable to use examples of class projects or to frame a learning experience as a project in itself – detailing how you went about learning something new.

“Use academic if you don’t have work-related examples.”

How to Prepare for a Technical Interview

When job seekers think about how to prepare for a coding interview, they will probably spend most of their time thinking about the technical interview. This one seems to scare people the most, but Katie stresses that all parts of the interview are equally important and that your level of coding ability should be equal to the task.

“What companies are looking for at this early careers level is very different to hiring a software engineer further on in their career.”

Interview coding challenges will vary, but typically, the technical interview might consist of a coding test sent to you by the company to complete, or they may ask you to present a project that you have worked on.

“Come prepared to talk about your code and documentation.”

Technical interviews do test your coding ability, but interviewers are still looking at those soft skills – evaluating how you tackle problems, follow instruction and seek and respond to feedback.

If the technical interview is project-based, then come prepared to talk about a project that you have completed in detail. Tell the interviewer about the project – what was it, what were you hoping to achieve, what language did you choose? And remember to mention any key considerations that came out of the project.

Don’t worry too much if you have a lack of work-related projects. Students who have been through Coder Academy’s Web Development Bootcamp will have built projects in class, and worked on various tasks and projects during their industry placement programs. In reality, however, anyone can devise and complete a coding project, and doing so will show your passion and commitment to ongoing learning.

If the company is asking you to complete a combined interview and coding challenge, then Katie recommends that you choose the language you are most comfortable using, rather than choosing one to impress the interviewer.

If you know that the company works with a predominant language or tech stack, then you can learn as much about this as possible before the interview, and talk about it with your interviewer, but for the test itself, it’s best to feel prepared with a language you know well.

“When you’re starting out we don’t expect you to be a guru in every language, even the language you’ve chosen to code in, we don’t expect you to know absolutely everything. What we look for is actually your ability to think and solve problems, and talk through your method, and sort of justify why you’ve chosen to do something a certain way.”

Being able to explain your work is a vital component of the technical interview. Spend some time in your coding interview preparation thinking about why you do things the way you do. As Katie points out, “there are about 25 different ways to solve the problems we send out.”

What interviewers are looking for is not the right answer, but how susceptible are you to feedback, and how you look to solve a problem.

Another reason Katie has for not fearing the technical interview, is that it is a learning experience in itself. Even if you aren’t selected for a particular role, you will have something to take away and use for your next interview.

The people who interview you are experienced programmers. This is actually a rare opportunity to gain access to some very senior people at different companies, and to experience the way that they work and instruct juniors.

Some Interview Coding Challenge Examples

One of the best ways to deal with your nerves as you prepare for a coding interview is to go into it having completed plenty of practice.

Katie says that some great interview coding challenge examples can be found via GeeksforGeeks. Alongside practice exercises, you will also find helpful articles and tutorials.

Don’t forget to check out the resources available through GitHub, either. Many people in the community have gone through the experience of coding interviews before you, and alongside written advice, you may even find others willing to give you specific examples and feedback. One day, you’ll be on the other side, and able to offer advice to the junior developers who come after you.

There are many other coding challenge examples out there, but one of the most helpful things you can do in your coding interview preparation is to practice and to compare notes with your peers.

Remember, You’re Not Alone

If you’re a recent graduate, then you already know a group of people who are going through the same process of applying for tech roles as you. If you’re from a smaller program, such as a bootcamp, then you know that the rest of the cohort are your allies, not your competitors. Make sure you keep in touch, and help each other along as you apply for jobs and prepare for interviews.

This doesn’t have to be complicated. You can share your most recent interview experience on Twitter and congratulate your peers when they post updates to LinkedIn. But you can also organise face-to-face or virtual meet-ups to go through mock interviews or coding challenges.

Share examples with each other, hold each other accountable as you practice and continue to learn together just like you did in class. You might even find job applications and interviews less daunting if you stop seeing it as an individual struggle and start seeing it as something your coding community is working on together.

Good luck out there!