SDET vs. Test Automation Engineer: Differences

Anushree Chatterjee

Software testing has evolved considerably over the years. Initially, testing was limited to checking the code. But as development procedures evolved (or got more complicated), just checking the code wasn’t enough. Creative solutions were needed to make sure that the application was tested thoroughly. However, with the boom in technology, deliveries started to get more frequent, meaning you had to release fully functional applications quickly. This meant that testing had to be integrated within the development process rather than being an afterthought – enter shift-left testing, Agile methodologies, and continuous testing. Since so much was being expected from software testing, the role of a “tester” also started evolving.

These days you’ll find testers going by different names – quality analyst, tester, QA engineer, SDET, automation engineer, and more. But the most common ones are SDET and test automation engineer. So, are all these names simply synonyms of each other, or are different expectations tied to each of them?

Wonder no more – this article will clear all your doubts.

What is an SDET in Testing?

An SDET (Software Development Engineer in Test) is someone who makes sure software is working perfectly by writing code that tests it, all while thinking like both a developer and a tester. They combine skills from both software development and software testing. They’re not just testers who find bugs; they are engineers who write code to build automated tests and testing tools. You’ll see SDETs work closely with software developers to understand how the system is built and create tests that can check if the software works as expected.

Imagine if you were building a car, and you wanted to test if every part worked correctly. An SDET would be the person who not only designs the test but also writes the code to automate it, making sure that the tests run smoothly every time a new part of the car is added or changed.

SDET Responsibilities

An SDET bridges the gap between testing and development. Their responsibilities tend to include:

• Creating Automated Tests: An SDET writes code to automate the process of testing the software. This way, the software can be tested quickly and repeatedly every time a new update is made.
• Building Testing Tools: They may also develop tools that help test the software more effectively, such as tools to test for performance, security, or compatibility.
• Collaborating with Developers: SDETs work closely with software developers to understand how the software is built and how it should behave so they can write the best possible tests.
• Debugging and Fixing Issues: When automated tests find problems in the software, an SDET helps identify why the problem happened and helps fix it.
• Integrating Tests into the Development Process: SDETs make sure that tests are part of the development pipeline, meaning they automatically run every time a new piece of code is added.
• Looking into Support Issues: Quite often, SDETs help analyze and potentially fix customer issues that come to the support team.

Skills of an SDET

• Programming: SDETs need to know programming languages like Java, Python, or C#. This helps them write test scripts and tools.
• Understanding of Software Development: They should know how software is built and how different parts work together so they can write effective tests.
• Testing Knowledge: Even though SDETs write code like developers, they also need to understand how to test software – knowing what kind of bugs to look for and how to organize tests.
• Problem-Solving: When tests fail or issues arise, SDETs must figure out what went wrong and how to fix it.
• Communication: They must be able to explain testing results and issues to developers, managers, or anyone else on the team.

Read: SDET Interview Questions: Your Key to Landing the Job

What is a Test Automation Engineer?

A Test Automation Engineer is someone who uses code to create tests that check if software works correctly, but their main focus is on automating the process. Instead of manually testing software by clicking buttons or entering data, they write scripts that automatically run these tests for them.

Test Automation Engineer Responsibilities

The main goal of test automation engineers is to make the testing process faster, more efficient, and less dependent on humans, especially for repetitive tasks.

• Automating Tests: Test automation engineers write scripts or programs that run automatically to check if the software is working as expected. This helps avoid doing the same tests by hand every time the software changes.
• Maintaining Software Quality: They test the software behaves correctly by running automated tests on things like buttons, forms, or features to check that they work right every time there’s an update.
• Reporting Bugs: When the automated tests find problems, the test automation engineer reports them to the development team so they can be fixed.
• Maintaining Test Scripts: They also update and maintain their test scripts to make sure they continue working as the software changes over time. Read: Decrease Test Maintenance Time by 99.5% with testRigor.
• Integrating with the Development Process: They make sure that automated tests run continuously as new updates or features are added to the software.
• Improving Test Coverage: They make sure that all important areas of the software are covered by automated tests, so no bugs are missed. Read: What is Test Coverage?

Skills of a Test Automation Engineer

• Programming: Test automation engineers need to know programming languages like Java, Python, or JavaScript to write the scripts that perform the tests.
• Knowledge of Automation Tools: They use special tools or frameworks to create and run automated tests.
• Attention to Detail: They must be careful and make sure their tests cover all the important features of the software without missing anything.
• Problem-Solving: When automated tests fail, they need to figure out what went wrong and how to fix it.
• Communication: They must be able to explain test results and problems clearly to the rest of the team, especially the developers.

Read: Top-30 QA Automation Engineer Interview Questions

SDET vs. QA

The roles of SDET (Software Development Engineer in Test) and QA/Test Automation Engineer both focus on automating the process of testing software. But there are some key differences in their approach, responsibilities, and the type of work they do.

Focus and Role

• SDET: An SDET is a hybrid role that blends software development with software testing. They are engineers who write code not only to automate tests but also to design and develop the testing framework and tools. SDETs are expected to have a strong software development background and a deep understanding of how the software is built so they can write tests that are tightly integrated with the development process. They also often work closely with developers to make sure that testing is built into the software from the start.
• Test Automation Engineer: A Test Automation Engineer, on the other hand, focuses primarily on automating existing tests for the software. They typically don’t build frameworks or develop testing tools from scratch. Their primary task is to write and maintain test scripts that automatically check if the software is working as expected. While they may know how to write code, they don’t necessarily work on the overall design of the testing systems or tools used in testing.

Role in the Development Lifecycle

SDET:

• SDETs are deeply embedded in the development process. They work alongside developers to make sure that tests are created and executed during the entire software development lifecycle.
• They help ensure that testability is built into the software from the start and that testing is integrated into the code development, not just an afterthought.

Test Automation Engineer:

• Test Automation Engineers typically join the project once the software has been developed and needs to be tested. They take existing test cases and automate them, making sure they can be run repeatedly and efficiently.
• Their main job is to reduce the manual effort of testing by automating repetitive tasks, but they don’t typically get involved in the design or architecture of the testing system.

Collaboration

SDET:

• SDETs work closely with developers because their role is to integrate testing into the development process. They design tests that check the code is working properly as it is being built.
• They also collaborate with QA teams to make sure their tests align with quality standards.

Test Automation Engineer:

• Test Automation Engineers mostly work with the QA team. They automate the tests that the QA team has already created, and their focus is on improving the efficiency of testing rather than designing or developing the tests themselves.

Difference Between SDET and QA/Test Automation Engineer

Conclusion

While both contribute significantly to automated testing, their responsibilities, skill sets, and involvement in the software development life cycle (SDLC) can differ substantially. SDETs take a more development-heavy approach, while Test Automation Engineers are more focused on automating existing tests. In the end, the aim is to achieve a good amount of test coverage so that you can rely on test automation for QA.

“We spent so much time on maintenance when using Selenium, and we spend nearly zero time with maintenance using testRigor.”

Keith Powe VP Of Engineering - IDT