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A Comprehensive Guide to
SDET Interview Questions

Achieve success in Software Development Engineer in Test interviews with this comprehensive guide. Master SDET interview questions with precision
For job hunting, interview questions act as a gatekeeper to your dream career. Navigating the intricate landscape of SDET interview questions can be challenging and crucial.

With the increase in establishing robust test practices in the software development lifecycle, SDET plays a pivotal role in ensuring the quality, reliability, and performance of software applications.

This guide aims to transform the interview process from a daunting challenge into an opportunity for you to showcase your unique strengths, accomplishments, and potential contributions. From general inquiries to specialized questions assessing your technical acumen, we will be showcasing to you the most powerful and most asked interview questions for the SDET position. Let’s begin our exploration with the top-asked SDET interview questions:

What is The Difference Between SDET and Manual Engineer?

Software Development Engineers in test (SDETs) are professionals who are equipped with both technical and programming skills. SDETs are more focused on creating automated test scripts to ensure the quality of the software. However, manual engineers execute testing manually without automation testing.

Your answer to this question showcases your understanding of the distinctions between a Software Development Engineer in Test (SDET) and a Manual Testing Engineer.

Share Your Understanding about Ad Hoc Testing ?

Ad Hoc testing is an exploration of the software to find bugs and defects. Testers execute tests without predefined scripts by using their domain knowledge. It is an effective method that uncovers unexpected issues in a software build.

This question is asked to evaluate your knowledge of unplanned testing that is performed without predefined test cases.

What are the Roles and Responsibilities of SDET?

SDETs play a crucial role and are responsible for a variety of tasks that include:

  • Creating and developing automated test scripts
  • Integration of testing and development process
  • Establish automated testing pipelines to enable frequent and reliable software releases.
  • Collaboration with cross-functional teams

Your response to this shows your comprehension of the multifaceted responsibilities associated with being a Software Development Engineer in Test.

What is Risk-Based Testing?

Risk-based testing involves identifying, assessing, and prioritizing testing efforts based on the potential risks to the software. This type of testing is focused on high-risk areas to mitigate the impact of potential defects.

The reason for asking this question is to test your grasp of understanding of prioritizing the testing efforts of a tester.

What is the difference between a Test Case and a Test Script?

A test case is a set of conditions designed to validate specific functionalities of the software. A test script is a sequence of automated steps written in a programming language. Test cases execute a test case automatically.

Answer this question to showcase your grasp of fundamental testing terminology and concepts.

Differentiate White Box Testing and White Box Testing ?

White box testing involves testing internal structures, code logic, and algorithms. For white box testing, it's imperative to boast knowledge of the internal workings of the software. However, black box testing focuses on validating external functionalities without the knowledge of internal code.

Your answer helps the interviewer to assess your understanding of testing methodologies.

Why are Test Plans Created?

Test plans provide a roadmap for testing activities. They outline the scope, objectives, resources, schedule, and approach for testing, ensuring systematic and organized testing efforts.

The interviewer asks these questions to explore your understanding of test planning in the software development lifecycle.

Explain Bug Report.

A bug report is a detailed document that describes discovered defects. It includes information on the issue, steps to reproduce, severity, and any other relevant details to assist developers in debugging and fixing the problem.

Your explanation showcases the ability to articulate and communicate issues during testing.

What are the Types of Bugs Detected by Fuzz Testing?

The types of bugs detected by fuzz testing can vary, but common categories include:

  • Memory-related bugs
  • Security vulnerabilities
  • Crashes and system failures
  • Protocol and communication errors
  • Parsing and interpretation errors
  • Performance issues
  • Functional bugs
  • Database vulnerabilities

This question is asked to assess the understanding of the specific types of issues that can be uncovered through fuzz testing.

What Do You Understand When the Product is Ready to Deliver?

When the product meets predefined acceptance criteria, has undergone thorough testing, and fulfills all requirements, it is considered ready for delivery to end-users or clients. This ensures a high-quality, reliable software release.

Your explanation describes your criteria for determining when a product is deemed ready for delivery.

What Are Alpha And Beta Testing?

Alpha testing is usually conducted internally by the development team to help identify bugs before the software is released externally. However, beta testing comes at the next stage where the software is exposed to a limited number of external users to identify the potential issues directly relevant to the real-world application.

You will usually be asked this question by an interviewer to determine your level of knowledge about each variety of test phase. When answering this question:
  • Ensure not to confuse the roles or purpose of alpha and beta testing.
  • Explain a situation where you would recommend conducting alpha testing or how you select the participants for beta testing.

Explain What Is Quality Assurance.

Quality assurance is a systematic process that ensures the overall quality of the software. To prevent defects, QA involves the establishment of a variety of standards and processes.

This question is asked to assess the understanding of broader quality processes in software development. While answering this question, avoid confusing QA with testing.

Typical Working Days of SDET.

The day in the life of an SDET majorly depends on the project stage, team structure, and responsibilities including team meetings to discuss progress, blockers, and upcoming sprints. Software development is a dynamic field that requires continuous learning to deal with industry trends.

Answer this question to provide the insight into daily responsibilities and workflow of an SDET. avoid providing a generic or unrealistic daily routine.

Explain What Is Load Testing.

In load testing, developers generate high volumes of concurrent requests to systems while measuring their performance under pressure. Stimulating real-world usage scenarios, this testing helps identify bottlenecks, capacity limits, and scalability issues before deployment. Several types of load testing are load types, metrics, analysis, and improvements.

This question is usually asked to assess your knowledge of performance testing. Make sure to avoid oversimplifying the explanation.

What Is Exploratory Testing?

In software testing, exploratory testing allows testers to design and execute test cases simultaneously. Testers explore the application and adapt their strategies based on real-time observations. This method of testing requires domain knowledge, creativity, and intuition to discover vulnerabilities and provide valuable insights into the software's functionality and user experience.

While answering this, make sure to
  • Define exploratory testing briefly.
  • Discuss its advantages in uncovering unexpected issues.

What Is a Test Plan?

A test plan provides a roadmap for a software project. It further defines the scope, objectives, resources, schedule, and methodologies for testing. It acts as a guide for the entire testing process that promotes alignment and ensures everyone in the development team is on the same page.

To answer this question, define what is the test plan and its components while ensuring not to provide an overly detailed or vague definition.

What Is Test Script?

A test script typically includes pre-conditions, test steps, expected results, and criteria to pass or fail. Test scripts can be manual or automated depending on the testing needs.

This question is most often asked to test the understanding of test execution. While answering this question, ensure not to confuse test scripts with test cases. Define a test script and explain its role in automated or manual testing.

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Briefly Explain Test Procedure.

An extensive document that outlines how to carry out a particular test case is called a test procedure. In addition to the standard steps in a test script, it includes extra information like data to be used, environment setup, and expected error messages. When the test case is executed, it guarantees repeatability and consistency.

Answer this question and discuss the importance of documenting the test procedure. Do not provide an overlay detailed or generic explanation. Instead, stick to what the test procedure is.

How Do You Approach Performance Testing, And What Tools Have You Used For It?

My approach to performance testing starts with understanding the system's expected load and performance goals. These include identifying critical business scenarios and creating scripts that stimulate realistic user behavior with design performance tests.
For tools, I used to select tools based on project needs. I've experience with tools like JMeter, Gatling, LoadRunner, and K6.

The interviewer accesses your knowledge of performance testing and relevant tools by asking about your preferred tools and techniques. Explain the importance of performance testing and discuss the tools that you have used or preferred to use.

Explain What is the Concept Of Continuous Integration And Its Benefits In The Development Process?

Continuous Integration is a developer’s practice that merges the code change into a central repository. However, automated builds, tests, and integrations are run on each code change. The benefits are:
  • Early bug detection
  • Improved code quality
  • Faster release of the software
  • Better team collaboration

Answer this question with much clarity as the interviewer tests your knowledge of modern software development practices.

What Are The Benefits Of Version Control Systems In A Software Development Environment?

Throughout the development, Version Control Systems (VCS) like Git and SVN monitor alterations made to the codebase. They offer numerous advantages that include tracking code history that helps in easily reverting to the previous version. Working on the same code base simultaneously with conflict resolution features. Plus, branching and merging create separate development environments to integrate changes.

In SDET interviews, your answer to this question showcases your understanding of version control and its impact. Focus on not overcomplicating the explanation with unnecessary technical details. Try to stick to what is exactly asked.

Explain The Concept Of 'Mocking' In Testing. When And Why Is It Used?

Mocking in testing stimulates external dependencies that allow testers to focus on core functionalities. This isolates specific parts of the system for thorough testing. Mock testing increases test execution speed as well as a control test behavior to test specific scenarios. Mocking is commonly used for APIs, databases, third-party services, or complex internal functionalities.

Answer this question to provide your understanding of advanced testing concepts. Avoid overcomplicating the explanation.

What Interests You About This Role?

My interest in quality and desire to create dependable software is what drew me to the SDET position. I like how testing requires a combination of technical expertise, original problem-solving, and teamwork.

Answer this by discussing specific aspects of the SDET role that excite you, such as the opportunity to combine development and testing skills.

How Techno Study Helps You Ace Your SDET Interview?

Software Development Engineer in Test (SDET) is a job role that requires more than just technical knowledge. It demands strategic preparation, hands-on experience, and mentorship. This is where Techno Study stands as a beacon in the industry, offering a high-quality SDET boot camp designed to elevate your skills, boost your confidence, and pave the way to success in SDET interviews.

With our unparalleled curriculum, real-world projects, expert mentorship, and interview-focused training, our customized learning journey maximizes your potential. Begin your journey toward SDET success with Techno Study!


Acing your SDET interview doesn't have to be an overwhelming challenge. The above-discussed SDET interview questions and their suggested answers help you achieve success. Practice your answers, delve deeper into specific topics that pique your interest, and cultivate your confidence.

Beyond technical, showcase your passion and collaborative spirit that can contribute to the team’s success. So, embrace your potential by preparing for your interview and secure your job.