Backend Online Coding Tests

Create and send backend assessments in 60 seconds, even if you’re not techy.
Hand over qualified backend candidates for your engineering team to interview.

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About our Backend Coding Tests

Our service equips your team with pragmatic and effective coding evaluations that accurately measure a candidate’s skill in backend. With tools like CoderPad Screen at your disposal, you have the ability to create backend coding evaluations in just a few minutes, even without a background in technology.

Our tests have been structured to include fundamental principles, algorithms, and beyond. These tests, painstakingly designed by our experienced industry professionals, guarantee that they reflect practical scenarios and are successful in gauging candidates’ competencies.

For hiring managers looking for a more personalized approach, we also offer the possibility of tailoring the test by adding their own coding challenges.

  • Recommended duration: 38-92 minutes
  • Average number of questions: 27
  • Type of exercises: Multiple choice, coding exercises, coding game, free text
  • Test levels: Junior, Senior, Expert

ℹ️ Explore our questions bank and test our candidate experience yourself

Backend Sample Questions

Example Question 1: Simple data processing

In this exercise, you have to analyze records of temperature to find the closest to zero.

Implement the method compute_closest_to_zero(ts) which takes an array of temperatures ts and returns the temperature closest to 0.


  • If the array is empty, the method should return 0
  • 0 <= size_of_ts <= 10000
  • If two temperatures are equally close to zero, the positive temperature must be returned. For example, if the input is -5 and 5, then 5 must be returned.

Example Question 2: Handling exceptions in Spring

Please look at the code snippet below. How does @ExceptionHandler work?


  1. If an exception of class A is thrown, runCode() is executed
  2. If there is an exception thrown in controller A, runCode() is executed
  3. If runCode() throws an exception, class A handles it
  4. runCode is allowed to throw exceptions of class A, but if it throws any other exception, compilation will fail

Example Question 3: Basic Django syntax

Select all the valid Django commands:


python migrationCode language: CSS (css)
python runserver

python makemigrations app1Code language: CSS (css)
python databaseCode language: CSS (css)
python shellCode language: CSS (css)

Example Question 4: PHP analysis

Implement the function findLargest(array $numbers) so it returns the largest number from the $numbers integer array.

Note: the array always contains at least one number.

<?php /*Starter code*/?>
function findLargest(array $numbers) {
     //Your code goes here
?>Code language: PHP (php)

Test code:

echo findLargest(array(7, 17, 13, 19, 5)); //19Code language: PHP (php)

ℹ️ Preview a sample coding test report

Explore Code Playback

Gain a deeper insight into the thought process and coding abilities of your developer candidates. 

  • Observe their algorithm-building skills and evaluate their approach and coding instincts.
  • Make a mental note of areas that you would like to explore further in subsequent discussions. 
  • Be vigilant in identifying any questionable or concerning behavior

How to test Backend skills to hire for your team?

Relying solely on resumes may not accurately represent a backend developer’s skills, and self-reported skills can be unreliable.

Here are five ways to assess backend developers’ coding skills:

  • Review their programmer portfolio, which showcases backend projects they have worked on and their proficiency in the language.
  • Examine their GitHub account to assess their backend code quality, activity, and involvement in backend-related projects.
  • Inquire about their use of Stack Overflow to gauge their knowledge level and participation in the backend development community.
  • Use programming tests tailored for backend developers, allowing them to solve practical backend problems and assessing their coding skills objectively.
  • Conduct live coding interviews specific to backend, where candidates can demonstrate their coding skills, problem-solving abilities, and knowledge of backend concepts.

💡 To dig deeper > 5 ways to test developers’ skills before hiring

How to approach initial candidate screening effectively?

Some recruiters may have concerns about testing candidates too early in the hiring process, as they fear it might offend or deter them. However, this doesn’t have to be the case. It is crucial to handle this situation appropriately to ensure candidates understand the purpose, feel their time is valued, and recognize their importance.

Follow these guidelines to incorporate early testing while ensuring a positive candidate experience:

  1. Job Ad: Clearly communicate that testing is the first step in your hiring process within your job advertisement. By setting this expectation upfront, you eliminate the risk of candidates feeling singled out for testing. Additionally, provide information about the time commitment required so that candidates can plan accordingly.
  2. Emphasize Fair Hiring and Diversity: Highlight how the testing process enables fair hiring practices and promotes diversity within your organization. Make it known that your focus is on assessing skills rather than judging candidates based on irrelevant factors. Convey that you are open to considering a diverse pool of candidates, including those without prestigious degrees or individuals starting their coding careers.
  3. Concise Assessment: Keep the assessment as brief as possible, respecting candidates’ time. Select an appropriate length for the test, including only the skills that are truly essential for the position. Ideally, aim for a test that can be completed within an hour or less. If you can design an even shorter test that fulfills your requirements, it’s even better
  4. Relevance: Concentrate solely on the skills that are directly applicable to the role. Avoid the temptation to create a laundry list of nice-to-have skills that are unnecessary for the actual job. Demonstrating a pragmatic approach by focusing on skills that have a practical impact on day-to-day tasks is appreciated by developers.
  5. Share Results: Provide candidates with their test results to ensure a more fulfilling experience. If you utilize a tool like CoderPad Screen, which automatically generates a brief report and sends it to candidates, you enhance their experience. Candidates who underperform will understand the reasons they weren’t selected for the next stage, and receiving results also serve as an additional incentive for completing the test.