Clean code test: Pre-employment screening assessment to hire the best candidates

Summary of the Clean code test

Clean code is the hallmark of a quality software engineer. Clean code can be the difference between wasting thousands on a project versus doing it right the first time. This screening test validates an engineer’s ability to write easy to maintain code.

Covered skills

  • SOLID Design Principles

  • Code Simplicity

  • Code Readability

  • Software Design Principles

Use the Clean code test to hire

Software engineers, software architects, programmers and coders of all types, as well as anyone else who uses or reviews code.


Programming skills


10 min





About the Clean code test

As an engineer, the last thing you want to refactor is spaghetti code. It’s time-consuming, wastes client funds, and is often one of the worst parts of writing code. This hiring test evaluates conceptual understanding of clean code principles through real-world scenario-based questions.

This hiring test uses language-agnostic questions to measure an engineer’s ability to write code that follows the SOLID, DRY, and YAGNI principles, and this screening test has a strong focus on “clean code,” as described by prolific computer scientist Robert C. Martin.

The test will also focus on implementation strategies, such as when to use an interface versus an abstract class and how to properly scope classes, properties, and more. High-quality code depends on high-quality documentation, comments, and naming conventions, and this hiring test includes questions on these important software development topics.

Wouldn’t it be nice to simply work on code that comments itself, lends itself to swapping out the old driver for a service for the new one, and just makes your life so easy that it rejuvenates your love for writing code? Use this test to recruit and hire developers skilled at clean code concepts! This screening test evaluates developers at an intermediate level (i.e., about two years experience).

The test is made by a subject-matter expert

Patrick M-G

Patrick has over 19 years of experience as a software engineer, with deep experience in RESTful frameworks. He is a published author on API integration and development, as well as a successful businessman, having built, scaled, and successfully sold a web development agency. He currently runs a new web development agency, and enjoys the flexibility and freedom of “vanlife” with his dog.

Crafted with expert knowledge

TestGorilla’s tests are created by subject matter experts. We assess potential subject-matter experts based on their knowledge, ability, and reputation. Before being published, each test is peer-reviewed by another expert, then calibrated using hundreds of test takers with relevant experience in the subject. Our feedback mechanisms and unique algorithms allow our subject-matter experts to constantly improve their tests.

What our customers are saying

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Review from G2

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I hope that TestGorilla realizes the value proposition in their work is not only the platform but the type of support that’s provided.

For a bit of context—I am a diversity recruiter trying to create a platform that removes bias from the hiring process and encourages the discovery of new and unseen talent.

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Review from G2

Use TestGorilla to hire the best faster, easier and bias-free

Our screening tests identify the best candidates and make your hiring decisions faster, easier, and bias-free.

Watch what TestGorilla can do for you the Clean code test

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The Clean code test will be included in a PDF report along with the other tests from your assessment. You can easily download and share this report with colleagues and candidates.

Clean coding skills test

What is a Clean Code test? How will it help you?

An online Clean Code test is a pre-employment skills assessment that helps you evaluate your engineer’s ability to write easy to maintain code. This Clean Code test based on tried and tested coding principles that produce exceptionally well-written code.

Until now, you may have struggled to find a simple hiring method that covers all the technical aspects of writing clean code. However, your search for expert-backed testing methods can stop here – our Clean Code test will help you hire the best.

An applicant with clean coding skills will provide plenty of advantages to your organization. Projects can become costly if your team members don’t write code correctly the first time around.

Having employees who can write clean code is essential to save time and money for your business. They will create code that others can read and understand and minimize the need to refactor poorly structured code.

Despite the clear benefits of having clean coders on your team, they’re not always easy to discover.

You may have narrowed the scope of your candidate search and tried to prioritize applicants who have a certification or degree.

Or you might be looking for applicants who understand well-known clean coding principles but lack an understanding of these principles yourself as a non-technical recruiter.

Alternatively, you may be having difficulty hiring a diverse team in a male-dominated industry due to unconscious bias, which can hinder productivity. What’s the ideal way to tackle these hiring challenges when trying to hire a top clean coder?

You can eliminate many hiring challenges by including this Clean Code test in your hiring process after candidate sourcing.

With the Clean Code test, you won’t need to review resumes and risk introducing bias into your recruitment process. The test will give you objective data that shows which applicants have the knowledge needed to follow clean coding practices.

Our expert-backed test also enables you to hire the right candidate even if you lack knowledge of clean coding principles. You can forget about unconscious bias once and for all and hire a diverse team with our test.

Clean coding skills test

Learn if your applicants have the 4 critical skills for writing clean code

Do you find it difficult to evaluate the essential clean coding skills? With this Clean Code test, you can evaluate the four crucial clean coding skills and hire a clean code developer with minimal effort:

An understanding of SOLID design principles: Applicants who pass this test know that the SOLID acronym refers to the principles of single responsibility, open-closed, Liskov substitution, interface segregation, and dependency inversion. You can gauge your candidates’ understanding of each of these principles with this Clean Code test.

Expertise in maintaining code simplicity: Use this test to determine whether your applicants understand how to keep their code simple and readable to improve its reliability and long-term usability.

Proficiency in enhancing the readability of code: Learn whether your applicants can improve the readability of code by writing accurate and thorough documentation and comments, using indentation consistently, grouping methods, and implementing consistent naming schemes.

Knowledge of vital software design principles: Use our Clean Code test to determine whether your applicants can use and implement vital software design principles, such as reducing coupling, increasing abstraction and cohesion, and improving code reusability.

Gauging your applicants’ clean coding skills is simple with our expert-created Clean Code test. The TestGorilla platform will automatically provide you with three different data sets for your applicants’ results.

You can check the length of time it takes candidates to complete the test, see applicants’ star rankings, and review their scores to see which candidate has the best clean coding skills.

Clean coding skills test

Choose this Clean Code test for convenient, effortless hiring

You’ll instantly notice that the Clean Code test makes hiring convenient and effortless. Here are some of the advantages of using the test:

Hire applicants without painstaking and time-consuming resume screening: When hiring clean coders, are you spending too much time painstakingly reviewing resumes? There’s a better, more reliable way: Incorporate this Clean Code test in your hiring process to completely replace resume screening.

Use the test once you’ve sourced applicants, and let the objective results show you the top clean coders in your applicant pool.

Assess and review your coders’ skills to create tailored training courses: The test results will reveal your applicants’ strengths, so integrate the test into your hiring process to set benchmarks and targets for your new hires when creating training courses. You can then use these benchmarks to help them grow their skills in specific areas.

Hire clean coders without unconscious bias: You’re probably aware of how important it is to hire diverse teams, but doing so isn’t easy in practice due to unconscious bias. That’s why our experts created this Clean Code test to help you avoid various biases. You can simply check the test results and let the objective statistics and data be your guide when hiring.

TestGorilla’s tests, including the Clean Code test, are quickly becoming popular with businesses across the world. Already, 6,000 companies are using them to make the right hires.

Oracle, Technicolor, and Publicis Groupe are just three organizations prioritizing skills testing with TestGorilla. Join them to make data-driven choices and hire the most skilled professionals.


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