Live coding interviews: do's and don'ts

Live coding interviews can be a massive source of anxiety for many developers — even the most seasoned — especially because the format can be intimidating. It involves a real-time interview — in person or remotely — where candidates must exhibit their coding skills by solving a live coding challenge within a predetermined time frame using a code editor. 

These interviews fall into two categories: whiteboarding, where the interviewee solves a task in front of the interviewer on a whiteboard, writing code by hand, or pair programming tests, where the interviewer and interviewee collaborate to solve a task in a simulated coding environment. 

Although many developers don't like these interviews, they're actually helpful. They give you a chance to prove your skills right there on the spot. With live coding, you can show how you solve problems, how creative you are, and how well you can explain things—all in just one interview. It's like putting all your skills in the spotlight at once.

Do's for the live coding challenge.

See what you must do to do well in live coding:

Ask Clarifying Questions First

In interviews, many engineers jump into the challenge and start coding immediately. Even though the urge to showcase your coding skills can steer you in that direction, it's better to take a step back initially, invest some time in understanding the problem thoroughly, and discuss it.

Hiring managers want to figure out a key aspect: Do you dive in headfirst even when you're not entirely clear? Will you dedicate hours to a project only to realize later that your solution doesn't address the core issue?

People often leave technical questions, especially those involving live coding, vague. This approach intends to test your ability to seek additional information. It helps them assess whether you consider constraints and potential challenges before delving into the coding part.

Feel free to ask any questions that come to mind or express any uncertainties you may have. This provides you with a more comprehensive understanding of expectations and equips you to avoid potential pitfalls while addressing the challenge.

Avoid making assumptions when uncertain. If you ask something that the interviewer is expecting you to think through the problem, they will reply, "That's a question for you to tackle."

If you need help thinking of a question to clarify things, start by examining the problem's constraints. Does it specify the kind of data you're dealing with? Is it restricted to integers, or could it involve strings, too? What should be done if the dataset happens to be null?

Talk Out Your Logic

Before delving deeply into the intricacies, briefly pause to outline your problem-solving strategy for the interviewer. Write a few strategic comments on the whiteboard. As you commence your coding, maintain a dialogue about your thought process. Imagine you're in a teaching scenario — What steps would you explain while working through the problem on a board?

If you find it challenging to code and talk simultaneously, you can begin with an introduction before diving into any actions and then return with an explanation.

"For now, I'm going to... and I'll circle back shortly to demonstrate my approach."

"As you can observe here, I'm..."

"Next up, I'll need to..."

"Give me a moment to wrap this up, and I'll walk you through my progress."

Frequently, if the interviewer notices you're veering off course, they might offer hints. They won't know you're getting off track if you remain silent while working. In coding interviews, hints aren't necessarily a negative indicator; they're curious to observe how you interpret and apply the hint.

Comment Your Code

Here's your golden opportunity to reveal your programming style to potential employers. Demonstrate that you adhere to best practices by incorporating succinct comments into the more intricate segments of your code. You need not be overly exhaustive; a mere hint that you're skilled in adding comments to your code will suffice.

Test Your Answer

Start testing with sample data as soon as you wrap up your solution. Not only does this exhibit a commendable trait to employers — being someone who validates their code — it can prove incredibly beneficial by helping you identify your blunders before they come to light.

Employ the provided constraints as your testing dataset. Frequently, our logic missteps lurk at the edges of the data range. The act of code testing not only leaves a strong impression on potential employers but also serves as your preemptive safeguard against potential mistakes.

Optimize Your Algorithm

Once you're sure your solution works, ask yourself aloud if there's a more innovative way. Businesses deal with big data, so avoiding unnecessary steps like sorting or extra loops can boost their product's performance. If you can be clever about this — or at least show you get it — it'll earn you different points with your interviewer.

Practice at home by figuring out how complex your solutions are. Find out which methods are slow and see if there's a better way. If you can go through data just once without sorting, go for it!

Always practice out loud; this will help you with specific language questions, especially if it's not your native language. This will boost your confidence and thoroughly prepare you for the interview.

Don'ts for the live coding challenge

See what you shouldn't do to do well in live coding.

Do not rush it.

While there's a time limit, writing the whole code is usually enough. Speeding through might lead to a compromise in the quality of your program.

Remember, time won't be on your side, and complexity might result in confusion or becoming stuck. Stick to simplicity; avoid overcomplicating things. Also, as long as your code runs, you can elaborate on more optimal solutions later.

Don't make it overly complex; Keep it straightforward. 

During the interview, nobody expects your code to be flawless. The key is having a working code by the end of the challenge, even if the solution isn't perfect.

Throughout the challenge, showcase your problem-solving approach: how you break down the problem, tackle it step by step, and move toward the solution. Prioritize efficiency to display your ability to create a well-thought-out design.

Don't panic if you get stuck.

In live coding challenges, anything can happen. If you hit a roadblock, be upfront about what's causing the hold-up, and share your thought process as much as possible. Usually, the interviewer will provide a hint to help you progress and continue tackling the challenge. Remember that you'll earn points for your effort, approach, and the reasoning behind your solution.

Don't forget to debug your code.

If there are any mistakes, there's no need to hide them. Explain what went wrong and how you identified the issue.

Don't let a live coding challenge deter you from the hiring process.

Coding challenges can be nerve-wracking, but often, the anxiety is worse in your imagination than in reality. Interviews are usually more relaxed than you might fear. The more you practice live coding, the more your confidence will grow.

Now it’s your turn!

Preparing for a Live Coding Interview can significantly impact your professional career. And remember: Creating connections and building relationships is at the heart of what we do at Olby. Being part of it gives you continuous support and access to resources for preparing and submitting job applications. Our team can help you understand the international job market and make it easier to find opportunities that match your skills. Join us today.