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How to Prepare for a Coding Interview: The Ultimate Guide

While stepping into an interview with the prospect of a new job or career should be exciting, it can also be both daunting and terrifying, particularly if this is your first Web development interview.
To ease any fears or worries you may be encountering, this guide will teach you everything you need to know to ace that upcoming interview. We’ll cover everything from the necessary preparations beforehand, questions and techniques you’ll encounter during the interview itself, and procedures you should follow after the big day. The goal is for you to perform confidently in conveying and showing that you have a lot to offer prospective employers!

How to Prepare for a Coding Interview

Stepping into the interview room and sitting down to begin answering a multitude of questions that sell the best version of yourself to the persons in front of you may feel like the most important aspect of the interview process, yet before that day even arrives, a solid foundation of research and preparation will be just as critical to your success.

Research, Research, and More Research

Begin by scrounging up all those juicy informative morsels you can get your hands on to give you a leg up during the interview itself.

Research the Company

Dig through the company’s official website to gain an understanding of what it is all about.  Use Google to track down press releases, news articles, blogs and even social media posts about the company.
Combine all this researched info into the most up-to-date account of what the company is best known for or what it is focusing on lately, which will provide you with an arsenal of information for your own questions or talking points during the interview.

Find a Current Developer

Browse through the company directories and dig into social media connections to locate a current or previous developer from the company. While you don’t want to force anyone into an uncomfortable situation, if the opportunity presents itself, getting in touch with one or two company developers can be a huge boon to your research endeavors. A company employee can provide a great deal of insight into the interview techniques the company uses as well as the day-to-day activities of the position for which you may be interviewing.
If direct contact with a current developer is out of the question, sites like Glassdoor are also a great resource and can provide useful insight into the “behind-the-scenes” of a particular company.  Just just remember the source of this information and beware: Not everything will be accurate or can be fully trusted on such sites.

Look Up Your Interviewers

Just as those interviewing you will be doing research for more information about you, do not be afraid to do the same for those that will be sitting across the table from you. Using LinkedInFacebookTwitter and other social media sites, you can start to develop a respectable profile for those people who will be interviewing you. You’ll then be able to leverage some of this inside information during the interview and make yourself stand out more from the crowd by showing an interest in or at least an understanding of those who are conducting your interview.

Profile Yourself

To be certain you have a solid presence online, take the time to establish your own active digital footprint:

  • Spruce up your resume as necessary to prepare for your interview, highlighting the most relevant experience or education.
  • Create a profile on a networking site such as LinkedIn or Stack Overflow for simple, professional communication.
  • Highlight your past work (both personal and professional) with an online portfolio. A personal website or an organized profile link on GitHub or another project repository will give others a good sense of the kind of work you do.

Practice Makes Perfect

An excellent technique, particularly if you haven’t taken part in a developer interview before, is to practice a peer to peer interview with a friend or colleague.
Ask your friend to review your resume and digital profiles to get a sense of you and what you’ve done or worked on. With that information in mind, your interviewer can then sit down with you and ask some of the most common interview questions you might face during the real thing. (Check out the next section for examples.)
While it may feel awkward to pretend with someone you know well, this technique can go a long way to alleviating any potential jitters and get you in the proper mindset to answer the types of questions you’re likely to face when the big day arrives.

Understanding and Coping with Interviewer Bias

Often unintentionally and even subconsciously, human beings have the tendency to make judgments and hold biases against others we encounter and interact with. The process of a job interview is no different, and this unfortunately can lead to interviewer bias, whereby the individuals across from you may make unintentional judgments based on all manner of social cues and influences out of your control.
Let’s briefly explore a few common types of bias you might face during a developer interview and some tips to alleviate the negative effects.

Contrast Bias

Contrast bias occurs when an interviewer notes a weakness in an individual and inaccurately compares that weakness against other candidates, giving the false illusion that other candidates are more qualified than they would otherwise be.
Tip: Ask questions pertaining to the strong skills or attributes the interviewer is seeking for the position. Find a way to tie that into your own experience or education to appear among the top of the candidate pile.

Halo Effect

The halo effect occurs when an interviewer gains an immediate positive feeling about a candidate, for virtually any reason, after which the interviewer becomes inherently positive when considering other aspects of the candidate, such as qualifications or work history. In essence, the interviewer imagines the candidate possessing a halo.
Tip: Since the potential causes of a halo effect can be virtually anything from the interviewer liking your fashion sense to you having lived in the same town as his or her second cousin twice removed, the best method for dealing with this and gaining your own halo is pre-interview research.  Find out what the interviewer likes to do in his or her spare time or even mimic the interviewer’s own style a bit, if possible.

Confirmation Bias

When an interviewer establishes a preconceived opinion or notion about a candidate, the interviewer has the tendency to seek out additional information or cues that support (or confirm) those already established ideas.
Tip: Do your best to emphasize your willingness to work with other team members and be open-minded. While you cannot readily recognize what manner of confirmation bias may exist within the interviewer, illustrating that you are flexible and malleable when appropriate is a strong tactic to illustrate an ability to change as necessary.
In all cases, the best tactics to cope with any potential bias you may face during the interview is to be open, positive, inquisitive and excited. If you appear to be genuinely interested in the proceedings and the people sitting across from you — as well as the position on offer — your interviewers will both consciously and subconsciously take note of that attitude.


The Interview

The Role of the Recruiter

If a recruiter has been involved in the interview process thus far, before stepping into that meeting, it may be beneficial to understand the role of the recruiter and how that role may differ from that of others conducting the interview.

Screening

Typically, the core responsibility of a recruiter will be to seek you out as a potential candidate and then go through the process of screening you for suitability. This will often involve verifying that you are interested in the position on offer and that you meet the basic requirements for the job (such as education or work experience).
This screening process typically occurs via telephone. The recruiter will often ask you to describe your past work experiences, education and qualifications necessary for the position. Should all that match up properly, recruiters will often be tasked with evaluating you from a behavioral perspective as well, with questions pertaining to how you would react (or have done in the past) in particularly stressful or difficult situations.

Providing Recommendation

Following the screening process, a recruiter will then typically offer the employer his or her recommendations of candidates, often rating candidates in some fashion to give insight into the relative qualifications and suitability of each for the position. From this information, the employer can then make a more educated selection of candidates to extend an offer of an interview.

Organizing

In some cases, the recruiter will be tasked with arranging the interview and coordinating logistics for everyone involved. In interview settings involving a larger team or a panel of interviewers, the recruiter may mediate the proceedings to keep questions on point and the interview on schedule.

Following Up

Following the final rounds of interview, often the recruiter will select the top candidates from the bunch and draft appropriate verification questions to ask of the candidates’ references. With that final information in hand, the recruiter discusses the best choice in his or her eyes for the position with the employer, and the final decision to make a job offer is completed.

Managing Nervousness

As much as we may not wish to admit it, even the most outgoing and extroverted among us can become victim to our own minds during an interview, letting nervousness get the better of us. Yet staying on top of those possibilities and practicing techniques to mitigate your nerves can give you a huge edge during the interview process and illustrate your calm and professional demeanor, which is most suitable for hiring.
Below, we’ll examine a handful of tips and techniques to help you cope with nervousness and keep yourself on task during the potentially stressful interview proceedings.

Rehearse

As outlined in the first chapter, “Preparation Is Critical,” one of the best techniques you can employ to deal with nerves is to practice the interview process ahead of time. Getting a friend to ask you a series of common interview questions will give you confidence going into the real thing.

Plan Ahead

The day or night before your interview, take the time to prepare everything from the outfit you’ll wear to the transportation route you’ll take to get there. Prepare your belongings and any tools you’ll want to bring with you, such as a notepad and writing utensil; your laptop, tablet or phone; and your physical resume and portfolio, if necessary. This will ensure you’re less nervous during the day because you’ve already considered all these critical details.

Simulate Confidence

Even if you do not feel confident when sitting across the table from those grilling you about your professional experience and past educational achievements, do your utmost to appear confident in your mannerisms and responses. If you feel you are becoming stressed or nervous and maybe fidgeting a bit, don’t be afraid to take a moment to gather your thoughts and take a deep breath or two before responding. Try to keep in mind that you were offered an interview for a positive reason, so try to ride the bit of confidence that knowledge can provide.

Speak Slowly

While you may feel robotic at first, particularly without practice or if you’re naturally a rapid speaker, the mere act of attempting to dial yourself back and talk slower than you might be inclined to can have a very relaxing effect on you. Not only will you be less likely to blurt something out you wish you hadn’t, but it sets the pace of your responses throughout the interview, giving you more time to consider and react when a particular inquiry comes in.

Humanize Your Interviewers

Try not to be intimidated by the people conducting the interview, but instead recognize that they, too, are humans, with their own emotions and nerves from time to time. Try to learn a bit about your interviewers ahead of time, and then, during the interview, find a natural segue to bring up that particular topic in conversation. This will not only make you feel relaxed when the process is more of a conversation and less of an interrogation, but those interviewing you will take note of your genuine interest and enthusiasm.

Typical Interview Techniques and Phases

A developer interview can consist of a number of stages or phases, but traversing this conversational gauntlet need not be difficult if you’re well aware of what to expect. Below, we’ll examine the typical phases of a developer interview, so you’ll be prepared for what is to come.

The Recruiter Interview

As detailed in “The role of the recruiter,” the first step in the process will likely involve a telephone or Skype (though sometimes in-person) interview with a recruiter. The recruiter is generally looking to screen you into or out of the possible candidate pool by asking about your education, experience, completed projects and the like.
As in any part of the process, be enthusiastic and honest, but remember to keep the recruiter’s intention in mind: to separate the wheat from the chaff. Ensure that you quickly discuss your ability to perform the job and any relevant education or experience you have while also emphasizing your willingness to be flexible and work with the team.

Technical Phone Screening

Often part of the recruiter’s role, the technical phone screen is where you prove your core competency with code and show that you belong in this Web developer position.
While there are a near-limitless number of possible tasks that could be asked of you during the technical phone screen, the common link between them all is for you to demonstrate a basic understanding of coding and development principles. You might be asked to write a simple method in JavaScript, stylize an HTML document in CSS, describe common data structures, explain object-oriented concepts and so on.
Typically, a recruiter will not be as technically proficient as a developer by trade, but he or she will know enough to determine if you’re pulling his or her leg at any time. Try to be prepared for this process by brushing up on your basic understanding of all aspects of coding and development.

Behavioral Interview

A behavioral interview involves questioning you in such a way as to learn about your typical behavior in past situations. In many cases, with candidates who are just entering the job market, there is very limited past experience, so the questions may be more geared toward the psychological reactions to theoretical scenarios (for example, “Describe an instance where you were facing a particularly difficult development problem and what steps you took to work through that issue.”)
The best technique to help you with this line of questioning is to pause and consider before every answer, taking enough time to consider how best to answer. Try to use specific, concrete examples you experienced in the past that relate to the question whenever possible.

Coding Challenge

Some companies include a coding challenge as part of the interview process since they can be predictive of a coder’s future success and lets interviewers see a candidate’s skills in practice. They can take as little as fifteen minutes to complete, on up to a few hours. While this may be intimidating to think about, it’s actually a great opportunity to showcase your skillset.

Puzzles and Brainteasers

Many interviewers like to include a puzzle or two into the process, seemingly to evaluate how you resolve problems with logic and reasoning, both of which are very necessary for development positions, of course.
Unfortunately, it turns out there is very little correlation between a candidate’s ability to solve brainteasers and his or her ability to perform the job being considered. While even Google has since dropped the practice, if you encounter a brainteaser during your interview process, all you can do is try your best to work it out. If the thought worries you, don’t be afraid to prepare a bit by looking up a few common interview brainteasers to get an idea of what the questions might be like.

Technical Whiteboarding

Another technique you may encounter during the interview is being asked to illustrate a technical concept on a whiteboard, either physically or digitally. While this can feel similar to the technical phone screen, typically the questions or concepts you’ll be asked to illustrate are more specific to the developer position and day-to-day work you’ll be taking on should you get the job.
Remember, it’s OK if your handwriting isn’t stellar (many developers are in the same boat); just make a joke and apologize for it before moving on!

10 Common Web Developer Interview Questions

While there are tons of possible questions you may encounter during the interview process, below we’ve outlined the top 10 general programming interview questions you may be asked, either directly or indirectly. Preparation of these will help build your confidence and set yourself apart from other interviewees who aren’t able to provide solid answers to these questions. Remember to practice answering these (ideally with a friend to act as the interviewer), so you’ll be fully prepared when the big day arrives!

  1. Tell me about yourself.
  2. Why should we hire you?
  3. What is your greatest strength?
  4. What is your greatest weakness?
  5. Why do you want to work here?
  6. Why did you leave your last job?
  7. What is your greatest accomplishment?
  8. Describe a difficult work situation and what you did to overcome it.
  9. Where do you see yourself in five years?
  10. Do you have any questions for me?

In addition to the above generic interview questions, there are also the technical, job-related questions that will come up related to the developer position you’re looking at. While there are far too many possibilities to list them here, spend some time looking over this list of common developer questions to get a sense of what you may be asked during your own interview.

Questions You Should Ask

While the majority of the interview will be the interviewer asking questions of you, it is critical that you aren’t afraid to speak up and ask questions of the interviewer. This can not only illustrate a true interest in the position/interviewers/company but can also express your drive to meet their needs and fit into the role they’re seeking.
Below are five useful questions to ask the interviewers when it feels appropriate to slip one in.

  1. What would you like me to accomplish in the first few months?
  2. What techniques or methods have been most successful for the company?
  3. How do you plan to handle [competitor/technology/etc.]?
  4. What are the common attributes of your best developers?
  5. What do employees do in their spare time?

10 Interview Tips Every Web Developer Should Know

In addition to everything we’ve covered for the interview thus far, we’ll conclude with 10 simple and useful tips you should keep in mind to give you that extra leg up when your interview rolls around.

  1. Dress professionally but comfortably. A good rule of thumb is to level up. If jeans are worn in the organization, then nice khakis or slacks with a clean pressed top would be appropriate.
  2. Bring your own resources and tools: pen and paper, computer device, resume, portfolio, etc.
  3. Ensure you have the proper travel itinerary, know the exact location and building you’re going to, and arrive 15 to 30 minutes early.
  4. Show genuine interest in the company, interviewers and position. Ask questions when appropriate, and be invested in the answers.
  5. Be passionate and enthusiastic when discussing your past work, education and experiences.
  6. Weave mentions of development-related resources you frequent into the conversation, such as development blogs or the social media of development firms.
  7. Discuss your own passion projects that you’ve worked on in your personal time.
  8. Talk about the next big things emerging in the development field that you may be excited about, such as a new technology or language.
  9. Avoid dangerous topics during the interview, such as discussing your expected salary (before prompting), lying or speaking ill of previous companies/co-workers.
  10. At the end of the interview, ask what the next steps are in the process, to establish a timeline and give you an idea of what to expect.

Post-Interview Protocols

Now that your interview is complete, you’re in the home stretch, but there are still a few tasks to complete and considerations to be made before you can rest on your laurels. In this chapter, we’ll cover what steps you should take after the interview has concluded that will keep you fresh in the minds of the interviewers and give you the best chance to get that offer.

Post-Interview Notes

As soon as you get out of the interview and have time to yourself, take a moment to jot down a basic outline of the proceedings. Make note of what aspects of the interview went well (or not so well), the technologies and activities you’ll likely be working on in that position, the people you’ll be working with, and what you would do differently in another upcoming interview, if applicable.
With the interview still fresh in your mind, you’ll be able to accurately get these notes down, so you can reference them later and don’t feel obliged to remember every little detail days or weeks from now.

A Quick Thank You

Once you arrive home after the interview, immediately send out thank-you messages, one to each individual interviewer. The purpose of this message is to thank the interviewer for considering you, to express your continued interest in the position, to ask any additional questions you may have thought of in the interim, and to provide any additional information to the interviewer that may be relevant. With this step complete, you’ll feel much more confident in the days to follow that the interviewer won’t forget about you when it comes time to make a decision.

The follow-up

The timing is dependent on your interactions during the interview, of course, but a few days or the following week after your interview, you’ll want to send out a follow-up email to the interviewers. The purpose of the follow-up is to remind the interviewers about you, to express your continued interest and excitement in the position, and to mention an idea or discovery that is relevant and that would be of interest to the interviewer or company.
For example, you might mention a possible solution you’ve thought of for a problem that was discussed during the interview or provide a link to an article or code project you discovered that may help with that problem.
It doesn’t take much effort on your part, but the act of writing this follow-up message shows you care and bodes well for your future when final considerations are being made.

Dealing with rejection and getting feedback

In the unfortunate event that you discover you weren’t offered the position, it is critical that you do your best to learn from the experience to improve your chances the next time around. Send the interviewer another email, and kindly ask for feedback. This feedback could cover any number of topics from your personality to your education or experience, but the important part is to try to remain open and receptive to the advice and feedback being provided.
While you may not agree with the evaluation or the outcome, keep in mind that the interviewer was interested in you initially for a reason, and thus your positive qualities can be combined with these suggested improvements to give you an edge during the next interview.
In some cases, the interviewer or recruiter may refuse to give feedback at all, for fear of legal ramifications or due to plain social awkwardness. While there is little you can do to get someone talking who doesn’t want to, the best technique to help your chances of receiving feedback is to be sincere, kind and even humble in your feedback request. An interviewer is far more inclined to want to respond and be helpful if he or she feels you’re open to whatever advice is offered.

Finally…

While stepping into an interview with the prospect of a new job or even career should be exciting, it can also be both daunting, particularly for your first Web development interview. While it can be somewhat overwhelming and even a bit scary to go down the road of the interview process at first, the prospect of a new job or even career that awaits you is extremely exciting and worth the trouble.
We hope this guide has provided you with all the information and tools you need to be fully prepared for your next developer interview and to begin that journey with that great new job that awaits you!