What is a whiteboard coding test, and does it work?

When hiring a software developer, you should be aware of the difference between candidates who have a basic understanding of a programming language and candidates who are experts in that language. Because knowledgeable programmers can write error-proof code more efficiently, it’s important to be able to evaluate applicants’ coding skills accurately.

Whiteboard coding tests are one way hiring managers have traditionally assessed applicants’ programming skills. These tests require candidates to solve coding challenges on a whiteboard in front of interviewers. However, these tests have several drawbacks.

The good news is that there are other ways to assess applicants’ coding skills during the hiring process.

Below, we’ll explain everything you need to know about whiteboard coding tests and explore a good alternative.

What are whiteboard coding tests?

Whiteboard coding tests are a class of interview questions that require candidates to work through coding problems on a whiteboard. They’re often used when hiring software developers or other applicants whose work requires a lot of coding.

Usually, employers conduct whiteboard coding tests in person, but you can also conduct them virtually. During an in-person test, the applicant stands at a whiteboard and writes solutions to coding problems while your hiring team watches. A virtual test might require the applicant to write on a digital whiteboard using video conferencing software.

 Prompts can include challenges like:

• Find the longest substring that includes only distinct characters in a string of text

• Swap one object for another without using temporary variables

• Merge two sorted linked lists

• Sort an array of integers of any size into ascending order

After receiving the prompt, the candidate must write out code that satisfies the problem on the whiteboard.

These tests don’t just ensure that candidates can solve a coding challenge. They also require candidates to explain their work and diagram their thought processes on the whiteboard. 

The idea behind these tests is that you and your hiring team can better understand the applicant’s approach to problem-solving. This setting also requires a candidate to communicate with your hiring team as they work.

How effective are whiteboard coding tests?

Companies have used whiteboard coding tests for decades. Historically, they’ve been particularly popular at software companies like Amazon, Microsoft, and Google. Following the lead of these large companies, many smaller startups have used whiteboard coding tests to hire developers. 

Many tech companies still use whiteboard coding tests in a limited capacity, but they’re nowhere near as prevalent as they used to be. Hiring managers now know the problems with these tests outweigh their benefits. Plus, many software developers are declining interviews with companies requiring whiteboard coding tests.

Let’s take a closer look at the pros and cons of whiteboard coding tests.

Pro: Whiteboard coding tests assess basic coding ability

These tests can provide valuable information about a candidate’s ability to solve coding challenges in real time. By watching someone code, you can better understand how they think through problems, how long they take to perform specific coding tasks, and whether they fully understand a programming language

Con: Whiteboard coding tests don’t reflect real-world programming tasks

Whiteboard coding challenges rarely reflect the type of work a software developer will do in the role for which they’re applying. Since whiteboard coding problems must be simple, they’re often more like software riddles than actual programming tasks.

Additionally, when working on real-world programming assignments, many software engineers simply copy existing code for basic tasks like sorting lists. There are huge databases of open-source code, and leaning on these databases is a lot more efficient than writing new code. So, the type of from-scratch coding that applicants must do during a whiteboard test is something they’d almost never do in a real work situation.

Con: Many candidates underperform on whiteboard coding tests

Another issue with whiteboard coding tests is that they put unnecessary pressure on job applicants. Research has found that programmers perform worse when forced to work in front of others instead of in private. So, there’s a good chance you aren’t seeing candidates at their best when you evaluate their coding skills using a whiteboard test.

Con: Whiteboard coding tests introduce bias into your hiring process

Whiteboard coding tests also create hiring bias and might negatively impact diversity within your business. These tests focus on the types of fundamental computer science problems commonly taught in college courses but not by coding bootcamps. Applicants who came to software engineering through non-traditional routes may perform poorly on a whiteboard test even though they could be a great fit for your company.

Because of these drawbacks, many companies are looking for alternatives to whiteboard coding tests for evaluating applicants.

Alternatives to whiteboard coding tests: Pre-employment tests

You can learn more about a candidate’s coding skills and approach to problem-solving without whiteboard coding tests than with them. The solution is to assess candidates using scientifically validated pre-employment tests that reflect the type of work that software developers will do at your company. 

Applicants can take your pre-employment assessment early on in the hiring process. This means you can identify the most promising candidates to invite for an in-person interview, saving your hiring team time and money.

Here are several ways you can implement pre-employment testing during your hiring process:

Assess candidates’ programming skills

TestGorilla offers a library of more than 90 programming tests for popular languages like C#, Python, Ruby, R, MATLAB, Java, and Go. Our tests are designed by experts and scientifically validated, so you can trust that applicants’ results accurately reflect their programming abilities.

Candidates can take these assessments remotely. That means applicants can find a quiet and comfortable place to work through questions, removing some of the stress of whiteboard coding tests. TestGorilla also lets you record candidates’ screens, so you can still see how long it takes them to solve specific coding problems.

Importantly, TestGorilla offers strong anti-cheating measures to ensure candidates’ results reflect their true abilities. These include time limits on tests and alerts that trigger when candidates switch to other windows on their computers.

Customize your programming tests

You can also add custom coding questions to any of our tests. These custom questions offer a great way to learn more about how candidates approach specific tasks and test their understanding of basic computer science principles.

You can use custom questions to ask the same questions you would during a whiteboard coding test. Since candidates don’t have to diagram their thought processes, you can also ask more complex questions that better reflect real-world coding tasks.

Incorporate personality and culture fit tests

Going beyond coding tests when evaluating job candidates is also important. You’ll learn the most about applicants by combining programming skills tests with tests for personality, cognitive ability, and communication skills.

Personality and culture fit tests are especially important if you’re hiring a software engineer to work on an existing team. It’s important to ensure the members of your software team work well together and can avoid conflicts that harm productivity.

Build curated programming assessments

With TestGorilla, you can combine up to five tests and associated custom questions into a single assessment. For example, you could evaluate a candidate on their C# skills, Java skills, personality, and culture fit in the same assessment.

Building multifaceted assessments enables you to learn more about your candidates than you can from a whiteboard coding test alone.

Use TestGorilla to find top programmers

Whiteboard coding tests, which require candidates to write code on a whiteboard in front of your hiring team, can help you understand a candidate’s approach to coding. But, they have significant drawbacks. Whiteboard coding tests don’t reflect the type of coding work applicants will do at your business, and they’re unfair to candidates who enter programming from non-traditional backgrounds.

Pre-employment testing using expert-designed coding assessments is a much more effective way to evaluate candidates for a software engineering job. With TestGorilla, you can build assessments using more than 90 programming tests, plus incorporate personality, culture fit, and communications tests.

Sign up for a free TestGorilla subscription today to build your first pre-employment assessment and start hiring better programmers.

You can also check out our guide to the best programming skills interview questions for help adding custom questions to your assessments.