QA Engineer vs. SDET: Holistic QA for Superior Software Solutions

The cost of poor software quality grew to at least $2.41 trillion in 2022, according to The Consortium for Information & Software Quality (CISQ) ​​Annual Report.

Factors like an overwhelming increase in cybersecurity breaches and the changing face of innovation through AI and other technologies have led the software industry to prioritize quality assurance (QA). In 2023, the software testing market size was valued at ~$51.8 billion. It is estimated to see a CAGR of more than 7% between 2024 and 2032.

With the changing face of innovation comes a transformation in QA roles and processes. Quality assurance (QA) engineer is a standard and traditional role in the QA sphere. Now, we also have software development engineer in test (SDET).

These monikers are sometimes used interchangeably, but the roles are different in terms of responsibilities, skills, and scope. At the end of the day, both QA engineers and SDETs are critical for building quality software solution

Defining QA Engineer vs. SDET

What is a QA Engineer?

QA has been used across disciplines for centuries. In software, however, the role of the dedicated QA engineer has only existed for a handful of decades. But today, it’s essential for ensuring product quality and functionality.

The QA engineer is responsible for evaluating the software and determining whether it meets the requirements of stakeholders and users. They plan testing processes and activities, create test cases and testing scenarios, and review them to ensure they cover all requirements. 

QA engineers focus on the functionality of software components, not the underlying code; they conduct black-box testing, not white-box testing. Typically, they evaluate software from a user’s perspective. 

Leveraging their deep knowledge of QA testing processes, tools, and methodologies, they conduct manual or automated testing, with an emphasis on catching bugs and defects. They also write reports with test results and findings and liaise with the developers to keep testing on track. QA engineers are not necessarily involved in the project in the early stages—they’re typically involved later on. 

What is a Software Development Engineer in Test?

The SDET is a newer role that has also become an integral part of the QA process. They are essentially a combination of developer and test engineer and must be skilled in both disciplines. 

SDETs design and develop automated test frameworks and scripts. Collaborating closely with the rest of the engineering team—developers, testers, and others—they develop tools that help testers with their jobs. They are important to planning and designing the product, with responsibilities such as reviewing the product code throughout the development lifecycle, writing unit tests, assessing the results of test scripts, and helping with debugging. 

Typically involved in the development process from the onset, SDETs ensure that the product is robust, reliable, and scalable.

QA Engineer vs. SDET Skills Comparison

QA engineers and SDETs are both dedicated to ensuring the quality of software products, so many of their skill sets overlap. For example, they must both have knowledge of testing frameworks and tools and an understanding of quality metrics. They should also have so-called “soft skills” such as attention to detail, strategic thinking, time management, and communication.

However, there are some areas where their skill sets diverge. 

QA Engineer

QA engineers focus on functional testing and must be adept at data management, bug reporting, and troubleshooting. They typically have limited programming knowledge, but they should understand tools like Selenium, Azure DevOps, TFS, Funtionize, and Cucumber, along with databases like SQL. They will also need to be able to empathize with the user.

SDET

The main skill set that separates QA engineers and SDET is the ability to code. Since SDETs are essentially a combination of developer and tester, they must be well-versed in both sets of technologies. That means they should know programming languages like Java, Python, and C#, as well as testing methodologies such as NUnit or MS Test and test management tools like Xray. They should also have experience with version control systems.

SDETs must also have a holistic understanding of the entire software development lifecycle and user needs.

When to Hire a QA Engineer vs. SDET

Some teams don’t need an SDET. For small tasks and less complex projects, a QA engineer will suffice. However, adding an SDET to the QA team can help you facilitate more comprehensive coverage. 

Agile teams in particular can use SDETs to improve and increase test automation, streamlining complex QA scenarios.

The roles complement each other. SDETs, for example, create the tests that QA engineers execute. Together, they improve software quality, catching more bugs and fine-tuning the product before release. 

Career Path and Growth Opportunities

SDETs and QA engineers work together closely. They also collaborate with other teams, particularly the developers. 

SDETs typically have higher earning potential, given their wider skill sets and involvement in the development and QA processes. In fact, some SDETs transition into their roles from a QA engineer background. Building programming knowledge enables the transition, increases earning potential, and helps future-proof skills. 

Conclusion

Both QA engineers and SDETs contributed to building better software. Even in a world that relies heavily on automation, manual testing is still important. 

At the same time, manual testing is not as prevalent, with automated testing dominating the scene. SDETs are becoming more prominent, while QA engineers are less common these days. Big tech companies like Amazon and Microsoft are steadily phasing out traditional QA roles and replacing them with SDETs. However, QA engineers will still be in demand for the foreseeable future. 

Along with this trend, there are many advancements, tools, and technologies to be on the lookout for in QA. For example, 68% of organizations are using generative AI to improve quality engineering, according to the World Quality Report 2024. All QA professionals will need to stay abreast of these shifts, such as by becoming adept in programming and gaining proficiency in specialized skills like AI and machine learning. 

Ultimately, organizations must assess their needs to determine their QA gaps and find the right roles and talent for their team.