What is a live coding interview? (Also known as a pair-programming interview!)
Today, you’ll learn how to use live coding interviews in the right way so that you can identify the best candidates. You’ll also get a list of the best live coding platforms.
Want to learn more? Read on!
What is a live coding interview?
Live coding interviews can be an effective tool to identify the right candidates. However, they’re not always popular among developers. That’s why you need the right type of live coding exercise to attract great candidates – one that prioritizes their experience and empowers them to shine.
Let’s take a look at what a live coding interview is, how to make them effective for finding the right candidates, and how to use them to improve your candidate experience.
What is a live coding exercise?
A live coding interview is a real-time and “face-to-face” interview where a candidate demonstrates their coding skills by solving a live coding challenge using a code editor in a set amount of time. Great live coding interviews are often highly collaborative. The interviewer assesses the code and the candidate’s problem solving skills and decides if the candidate moves on in the recruitment process.
Live coding interviews can either be whiteboarding (the interviewee solves a task in front of the interviewer on a whiteboard, writing code by hand) or pair programming tests (the interviewer and interviewee collaborate to solve a task in a simulated coding environment). Pair programming assessments can take place in-person or remotely, depending on what works best for a team and their candidates.
The benefit of this type of coding test is that you see how developers work in real-time. You get a feel for how they work versus just the end product, which you may miss out ont with a take-home coding challenge or other asynchrounous assessment. With live coding, you can better assess things like how your candidates solve problems, how creative they are, and how they communicate, all at once in the same interview.
That said, live coding exercises are a hot topic in the developer world. The main criticism is that live coding tests aren’t always representative of the actual work a developer would perform as part of their job.
Plus, live coding interviews can be stressful for candidates, which again may affect developers’ performance.
Both of these points are valid. A study by North Carolina State University and Microsoft shows that whiteboarding tests can affect candidates’ performance due to the extra pressure of these coding tasks. Fortunately, there are ways to fix your interview process.
First, you can weed out tasks that make no sense for candidates or your recruitment process (like a binary search). Try to find a good balance between using exercises that represent tasks your developers would work on, but don’t require first-hand knowledge that would make the test unnecessarily difficult to solve.
Second, a live coding interview shouldn’t be about someone “passing” or “failing”. Instead, look at whether they got anything at all to work versus whether they completed the entire exercise. That way, they don’t feel pressured about completing their task “in-time”, and the test becomes more about the process than the end result.
And before the interview, let candidates know what the coding test will be about, how it will be conducted and by whom, which tools they’ll be expected to use, and which skills you will assess. When possible, let them use their own device and developer environment with the language and framework they prefer to use.
Given that pair programming allows candidates to perform in a more native environment, they can be a slightly less nerve-wracking experience than writing code on a whiteboard, so giving preference to pair programming tasks over whiteboarding can be a good idea and ultimately, a better predictor of future performance.
What’s more, you can start with short exercises that increase in difficulty to boost candidates’ confidence. And you might even let them choose their own tasks among different alternatives so that the test becomes more about assessing skills rather than scoring on a test.
On a final note, remember that coding tests only cover certain skills and behaviors. The rest of your interview process should help you evaluate your candidate as a whole.
Live coding interview questions
What are the best live coding interview questions? Depending on the live coding interview platform, you can typically use your own tasks or choose from a task library.
Either way, your interview questions should not be overly difficult. Keep the testing time to around 45 minutes.
The task should be a real-world task; something your candidates would work on as part of their job.
For instance, here’s a take-home task from our CodeSubmit task library:
As you can see, this task isn’t theoretical but asks candidates to develop a real feature. In the same way, you can create a live coding task (or use a pre-existing task) that asks them to solve a problem or create a feature that they can complete in under an hour.
A few example live interview questions are:
“Find the size of a Set in Python.”
A Set is an unordered collection data type. The size indicates the amount of memory occupied by a set object.
“How do you print multiple arguments in Python?”
An argument is a value that’s passed within a function when it’s called. During the time of call, each argument is assigned to the parameter in the function definition.
“Find duplicate characters in a string in Java.”
To find duplicate characters, candidates count the occurrence of each character in the string. If the count is greater than 1, the character has a duplicate entry in the string.
“Remove duplicate elements from ArrayList in Java.”
To remove duplicate elements from the ArrayList, candidates need to create another ArrayList and traverse through the first ArrayList to store the first appearance of each element into the second ArrayList using the contains() method. The second ArrayList contains the elements without duplicates.
At what stage to use live coding interviews
When in your hiring process should you use live coding interviews? Great question. There's no right or wrong, but typically, you'll create the best hiring processes by holding your sessions after the first one or two interview rounds and before you hold your final one our two interview rounds.
If you hold them too early, you'll potentially have a lot of candidates to go through. And if you hold them too late, your hiring decision might be more steered by hidden bias than candidates' actual skills and abilities.
The best live coding platforms
Now you know how to conduct a live coding interview. But what are the best live coding platforms? That’s what we’ll look at now.
The features you’ll want to keep track of include which languages/frameworks a coding platform supports, whether or not candidates can use their own environment, whether the platform also supports pair programming, and customer support.
CodeSubmit is a technical assessment platform for teams of all sizes. The platform supports 65+ languages and frameworks and offers live pair-programming environments with CodePair, as well as asynchronous take-home assessments. You can run candidates’ code right from your browser with CodePlay™, and with CodeSubmit, candidates can use their own IDE to complete tasks.
- Supports 65+ languages and frameworks
- A library of over 350 real-world coding challenges
- Supports candidates’ own IDE
- Options for pair programming, take-home coding challenges, and shorter screening tests (CodeSubmit Bytes)
- Best-in-class customer support
- Custom branding that supports your employer brand
- Integrated audio/video/chat in CodePair
Starts at $99/month with plans for startups, scaleups, large businesses, and enterprises.
HackerRank offers a real-time pair programming environment with a virtual whiteboard. As one of the first live coding platforms, it’s especially popular with enterprise clients. HackerRank uses a customizable IDE environment.
- Supports 40+ languages
- Content library
- Customizable, developer-friendly editor
Starts at $25/month with plans for solo interviewers, teams, and enterprise platforms.
HackerEarth’s FaceCode is an online coding interview platform for pair programming sessions. It comes with a collaborative code editor, question library, a diagram board, and more.
- Supports 41 programming languages
- Automated interview summaries
- AI-based behavioral insights
Starts at $119 with options for startups and enterprises.
CoderByte offers a platform for remote interviews and code-pairing in a live programming environment. With the platform, you can create lightweight interview templates and simulate whiteboarding sessions.
- Supports 30+ languages and skills
- Automated grading & reporting
- Built-in capability to browse developer resources
Starts at $199/month with a pay-per candidate plan. Plan with add-ons (including support, API integration, and custom branding at +$330/month).
Codility offers a live coding platform, CodeLive, for whiteboarding and pair programming sessions. One of Codility’s primary benefits, for those teams that require such a tool, includes the shared canvas for collaborative mockups.
- Supports 40+ technologies
- Whiteboard interviews
- Shared canvas for collaborative mockups
No pricing information available, you’d have to contact their sales team.
HireVue offers a platform for video-enabled coding sessions for later stage technical interviews. The company positions itself for bigger companies (2,500-7,500 employees) and enterprises (7,500+ employees).
- Supports 40 languages
- Auto-scored coding assessments
Starts at $35,000 with options for enterprises. Note that coding assessments are an add-on.
Over to you!
There you have it! Now you know what a live coding interview is. Plus, what the best live coding interview platforms are.
Want to get started right away?