SDET vs QA – What are the top 10 key differences?

Test Scripts_banner image

Start automating your tests 5X Faster in Simple English with Testsigma

Try for free

SDET vs QA: Decoding the Mystery!

Ensuring software quality requires two crucial roles: SDETs and QAs. While both aim to deliver bug-free products, their approaches and skill sets differ. 

Understanding these distinctions can help you choose the right career path or build an efficient testing team. Let’s dive into the top 10 critical differences between SDETs and QAs, unraveling their unique contributions to software development.

SDETs and QAs

What is SDET?

An SDET, or Software Development Engineer in Test, is a unique role that blends development and testing disciplines. 

They are more than just testers; they act as bridges between development and QA teams, wielding coding prowess and testing expertise to ensure software quality throughout its lifecycle.

Here are some key characteristics of an SDET:


  • Programming: Proficient in programming languages like Python, Java, JavaScript, etc., and familiar with testing frameworks like Selenium, Appium, etc.
  • Testing Expertise: Deep understanding of testing methodologies like functional testing, performance testing, security testing, etc.
  • Analytical thinking: Ability to identify and analyze potential issues and develop effective test cases.
  • Problem-solving: Strong problem-solving skills to troubleshoot and resolve testing challenges.
  • Collaboration: Ability to collaborate effectively with developers and other stakeholders.


  • Developing and maintaining automated test scripts: Writing code to automate test cases, improving test coverage and efficiency.
  • Designing and implementing testing frameworks: Creating custom frameworks to support specific testing needs.
  • Executing and analyzing test results: Running tests, analyzing results, and identifying bugs or defects.
  • Collaborating with developers: Working closely to fix bugs, improve code quality, and ensure testability.
  • Staying up-to-date with testing trends and technologies: Continuously learning new technologies and methodologies to enhance their testing skills.

What is QA?

QA, or Quality Assurance, is vital in ensuring the quality of software, products, and services. It encompasses a wide range of activities and processes to identify and prevent defects before they reach customers.

What is QA

Members of the Quality Assurance team are called QAs or Quality Assurance Engineers. 


  • Delivering High-Quality Software: QAs strive to guarantee the software meets its intended purpose, functions flawlessly, and provides a positive user experience.
  • Identifying and Fixing Issues: They use various testing methodologies to uncover bugs, usability problems, and performance bottlenecks.
  • Improving Software Quality: QAs actively contribute to improving software quality by suggesting improvements, participating in code reviews, and collaborating with developers.

Key Responsibilities:

  • Designing and Executing Test Cases: QAs create comprehensive test plans covering different functionalities, user scenarios, and edge cases. They then execute these tests manually or through automation tools.

Get updated information on Top Test Automation Tools today

Check out
  • Analyzing Test Results: QAs carefully evaluate test results, identify issues, document them clearly, and prioritize their severity for efficient resolution.
  • Reporting and Communication: They communicate test results and identified issues to developers, stakeholders, and project managers, ensuring everyone is on the same page.
  • Staying Updated: QAs remain informed about the latest testing trends, methodologies, and tools to adapt their approach and optimize testing effectiveness.

Types of QA:

  • Manual QA: Primarily involves manual software testing, often focusing on usability and user experience.
  • Automation QA: Utilizes automated web application testing tools to execute repetitive tests, improving efficiency and coverage.
  • Performance QA: Tests the software’s performance under various loads and conditions, ensuring responsiveness and stability.
  • Security QA: Focuses on identifying and mitigating potential security vulnerabilities in the software.

The value of QA and SDETs in Agile development

In Agile development, both QA and SDETs have really important expertise. 

QAs act as quality control, testing, and discovering issues throughout sprints. Their deep understanding of testing methodologies ensures comprehensive coverage, while clear communication with developers fosters rapid bug fixes.

SDETs, with their coding prowess, bridge the gap by automating tests, building frameworks, and collaborating on design. This proactive approach identifies potential issues early, saving time and ensuring high-quality releases within each iteration. 

QA and SDETs form a dynamic duo, safeguarding quality and propelling successful Agile development.

QA and SDETs

SDET vs. QA – Core Differences

The term SDET is often used to describe a software developer specializing in creating automated testing frameworks and tools. Unlike traditional testers, SDETs are responsible for writing and maintaining the code that drives computerized tests. 

In addition to their coding skills, they must also deeply understand software testing fundamentals and best practices. This is because they are responsible for ensuring that the automated tests are effective and reliable and cover all aspects of the application under test. 

On the other hand, a QA is a professional who specializes in executing automated tests. They typically work with a set of pre-existing computerized tests and are responsible for running them on different software builds. 

Unlike SDETs, automated testers do not write or maintain the code that drives the automated tests. Instead, they focus on ensuring that the tests are executed correctly and that the results are accurate.

Technical Expertise:

  • SDET: Possesses advanced programming skills and in-depth system knowledge, allowing them to build custom test frameworks, contribute to code, and perform complex API testing.
  • QA: Typically has basic programming skills focused on scripting for automation. Their expertise lies in test case design, manual testing, and using pre-built test tools.


  • SDET: Owns the entire testing process, from designing and automating tests to analyzing results and collaborating with developers on improvements.
  • QA: Focuses on executing specific test cases assigned by SDETs or leads, providing feedback, and reporting issues.

Outgrowth Involvement:

  • SDET: Actively participates in the development lifecycle, collaborating with developers to identify potential issues and suggest improvements.
  • QA: Typically joins later in the development cycle, focusing on testing the completed product.


Due to their technical expertise and domain knowledge, SDETs may provide guidance and direction to QAs, especially in areas requiring programming skills.

QA and SDETs

Here’s a simplified table summarizing the key differences:

Main GoalImprove system quality through automation & thorough testingImprove system quality through test execution & reporting
Main ResponsibilityOwn the entire testing processExecute specific test cases
Programming SkillsAdvanced programming skills are neededBasic programming skills are enough
System KnowledgeAn in-depth understanding of system knowledge is necessaryFocus on the tested area is enough
Development InvolvementActive throughout the lifecycleJoins later in the cycle
Role HierarchyCan become a lead/guide QAsReports to SDETs or leads


Choosing between an SDET and a QA often hinges on your project’s specific needs. For intricate testing landscapes or projects demanding deep system understanding, an SDET’s combined skillset shines. 

On the other hand, when robust manual testing and clear communication are paramount, a QA’s expertise excels.

I would say, 

“By fostering communication, leveraging complementary strengths, and embracing a shared passion for quality, both SDETs and QAs can ensure your software sings its sweetest melody.”

Happy Testing!

Suggested Reading:

Testing kpis


Can an SDET and a QA engineer work together?

SDETs and QA engineers make a powerful combination. SDETs build automation frameworks while QAs dive deep into testing, creating a comprehensive approach to software quality.

How can I choose between becoming an SDET or a QA engineer?

Consider your strengths! 

Do you love coding and building tools? SDET might be your jam. 

Are you passionate about meticulous testing and user experience? QA could be your perfect fit. 
Remember: Both roles are crucial for software quality!


API Examples: A Complete List of 10 Use Cases


Grey box testing: Techniques, Process & Example


How to Write Test Cases for Notepad? [Sample Test Cases]