35 Important SDET Interview Questions With Sample Answers

A software development engineer in test (SDET) role involves developing software tools, frameworks and automated tests for software testing purposes. When hiring for SDET positions, employers test software engineers on their technical knowledge of software development core concepts and automation testing processes. By understanding the type of questions that employers typically ask during SDET job interviews, you can prepare well, make a good impression on interviewers and improve your chances of getting a job offer.

In this article, we provide a list of commonly asked SDET interview questions and give sample answers for some of these to help you practise for your interview.

10 General SDET Interview Questions

Interviewers, when hiring for this role, usually start with the following general SDET interview questions:

1. Why did you decide to work as an SDET?

2. Why do you want to work with our company?

3. Where do you see yourself career-wise in five years?

4. How do you stay updated with industry trends?

5. Can you tell us about a professional achievement you are most proud of?

6. What are your strengths and weaknesses as a software tester?

7. What have you done to overcome your weaknesses as a software tester?

8. What are some of the software development publications and blogs that you read regularly?

9. Can you tell us about a book that you read recently?

10. What are some of your interests outside of work?

Related: What Is The Role Of A Software Development Engineer In Test?

10 Questions About Experience And Background

After getting an idea of your personality with the general questions, the interviewers may enquire about your educational background and work experience as an SDET with the following questions:

1. What skills do you require to work successfully as an SDET?

2. What do you do to update your software testing skills?

3. What do you like the most about working as a software tester?

4. What are some of the software testing projects you participated in in your previous role?

5. What is a typical workday like for you as an SDET?

6. What methods do you use to stay organised with multiple projects and deadlines?

7. What approach do you take when beginning a new software testing project?

8. Did you ever have a professional disagreement related to testing specifications, and how did you resolve it?

9. Do you plan to upgrade your skills with additional software testing certifications?

10. What can you accomplish in the first 90 days if we hire you?

Related: What Is Relevant Experience? (With Examples And Tips)

10 In-Depth SDET Questions

You can expect the following in-depth questions to test your technical knowledge:

1. What is the difference between quality assurance and quality control?

2. What software testing tools did you use in your previous SDET position?

3. What is the difference between performance testing and load testing?

4. How does Equivalence Class Partitioning work?

5. What types of bugs can you detect with fuzz testing?

6. What are some of the test scenarios you ought to cover before a mobile application release?

7. How would you reverse a string in Java?

8. Can you list some advantages of the automation framework?

9. What is your method for testing for operational defects?

10. What are the advantages of code inspection in software testing?

Related: Top 101 Software Testing Interview Questions (With Answers)

5 SDET Interview Questions With Sample Answers

You can refer to these interview questions with sample answers to prepare for your upcoming job interviews:

1. What is the difference between SDET and manual testers?

Interviewers often start an SDET job interview with this question to test your understanding of the role. You can explain what an SDET does and what a manual tester does. Then you can discuss some differences between them.

Example: 'A software development engineer in test (SDET) is skilled in software development and software testing, while a manual test is only concerned with the software testing process. While a manual tester is only involved in the testing phase of software development, an SDET is present throughout the software development process. SDETs develop test automation tools and frameworks and may use multiple testing techniques to conduct security, functional and non-functional and other tests. Manual tests do not create automation tools and frameworks, while their testing scope is generally limited to checking the application's functionality.

SDETs undertake white box and black box testing, while manual testers only do black box testing.'

Related: Accessibility Testing Tools (Definition, Types And Examples)

2. What are the professional responsibilities of an SDET?

This is a common interview question you may encounter when interviewing for an SDET position. The purpose of asking this question is to learn about your work experience in this field. You can respond by listing some responsibilities you had in your previous positions.

Example: 'In my previous position, I was involved in designing data, products and user interfaces. I also built automation solutions to conduct performance, functional and regression testing. I also carried out customer research to understand customer requirements and collaborated with the technical support team in investigating problems customers were having with our applications.'

Related: Essential Automation Testing Tools To Enhance Efficiency

3. What is the difference between priority and severity in software testing?

Understanding a bug's priority and severity is essential for SDETs as the issues can impact the client's business. When interviewers ask this question, they may expect you to explain the meaning of the terms. You can also list some differences between priority and severity.

Example: 'In software testing, priority refers to the importance of the issue and the order in which it is necessary to resolve the problem. For example, consider a high-priority issue, such as a software defect that renders the system unusable. In such a case, you can prioritise it over other flaws that do not affect the application's functioning and fix it quickly.

Severity refers to the impact or the influence the issue has on the product you are testing or its users. When the product has a high severity rating, the defect can impact the functionality of the application. Typically, the product may not require instant fixing unless it is also a high priority.'

4. What is risk-based testing?

As an SDET, it is essential for you to consider the risks that can occur in a software programme because of software complexity, frequency of use and potential defects. That is why interviewers can test your knowledge with this question. You can answer by explaining what risk-based testing is and the benefits of carrying out this type of testing.

Example: 'Risk-based testing is a strategy for testing the functionalities of a software product based on the premise that risk might occur. A risk can be any unknown and unexpected event that can cause a positive or a negative effect on the success of the software product. Since these risks can impact the product's technical features, quality, cost and market demand, it is crucial to conduct risk-based testing on software products.

By checking the product for negative risks, it is possible to reduce or eliminate threats that can derail the product's success. Positive risks can include innovating new products, improving development processes and investing in new projects. Getting informed about them can open up new opportunities for the company's long-term business success.'

5. How would you create an automation strategy from scratch for a product?

Interviewers ask this question during SDET job interviews to test your technical skills and knowledge. It is an open-ended question that allows you to discuss your professional experience in automation. You can provide examples of automation strategies you used when building a product in your previous position.

Example: 'For products that have never undergone automation testing, consider designing an automation framework that uses a commonly understood programming language and technology. It is customary to automate the most basic functional scenarios first. You can use automated test tools to test the system for performance and scalability. You can check the security standards in the Open Web Application Security Project (OWASP) to automate the application's security controls. To get early feedback, you can integrate the automated tests in the build pipeline.'

Related: Automation Testing (With Definition, Types And Benefits)

SDET Interview Tips

The following tips may help you prepare better for the upcoming SDET job interview:

• Research the company and its products. You can get the necessary information from the company website and social media content and searching for information on search engines. You can go through its applications to learn about the type of automation they require, check for any functionality issues and find out about the challenges that users might face.

• Improve your SDET capabilities. Review your knowledge of performance testing, functional testing, load testing, security testing and automation framework. Reread information about the different tools useful for this role.

• Practice your coding skills. As an SDET, you require high-level expertise in multiple programming languages. Work on strengthening your foundational concept of programming and writing production-level.

• Develop your communication skills. You require strong verbal, written and listening communication skills to interact with your team and stakeholders. Employers assess candidates for their communication and collaboration abilities during job interviews.

• Increase your confidence with mock interviews. You can ask a family member, friend or colleague to interview you and give feedback on your performance. You can also video record the mock interview and assess areas you can improve to enhance your confidence level.

Please note that none of the companies, organisations or institutions mentioned in the article are associated with Indeed.