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

Indeed Editorial Team

Updated 26 January 2023

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

A software developer, apart from coding, learns many other skills that enable them to perform multiple functions within the Software Development Life Cycle (SDLC) and beyond it. They can work in many roles, like business analyst, technical recruiter, project manager, product manager, scrum master, DevOps engineer and technical writer. If you are interested in a career in software development, you may also consider the job role of a software development engineer in test (SDET). In this article, we examine what is an SDET is, what duties and responsibilities they have and the skills required to become one.

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What Is A Software Development Engineer In Test?

A software development engineer in test (SDET), also called developer in test, is a computer industry professional who can produce and assess code to make automated testing programs. They customise testing programs to evaluate code based on a variety of parameters they choose. An SDET can assess the code, identify errors and bugs and make changes as required. Their primary aim is to enhance the end-user experience by developing and delivering automated testing programs.

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Why Is The Role Of A Software Development Engineer In Test Important?

Many organisations use agile methodologies, DevOps or continuous testing for their software development projects. Developers use methodologies that enable them to complete the SDLC efficiently within a proposed timeline and budget. To achieve this, testing has to happen quickly and often simultaneously, for developers to get feedback in real time and make changes. In traditional methodologies, testing happens only when the team completes development.

An SDET can create tools and frameworks for automation, planning, manual testing and for documenting test cases. An automated testing programme removes the need for repetitive manual testing and reduces the duration of a software development life cycle significantly. They are crucial for delivering high quality and bug-free products at an affordable price.

Related: What Does a Test Engineer Do? Duties and Responsibilities

What Does A Software Development Engineer In Test Do?

An SDET does the work of a developer and a tester. The main expectation from their role is that they reduce the need for repetitive manual testing and increase testing efficiency. Some key duties of software development engineer in test are:

  • Establishing, monitoring and scheduling automated testing processes: The primary duty of an SDET is to write software that runs tests on existing programs. Therefore, one of their primary duties is to write code for automated testing mechanisms and to check them for efficiency.

  • Identifying and troubleshooting issues with automated tests: If errors occur in the automated testing software code, the SDET rectifies the errors to improve the test's efficacy. The SDET may identify the errors themselves, or a manual tester or customer may report the errors.

  • Improving existing testing methods and designing new ones: Besides making new automated tests, SDETs may improve upon existing test code or design faster and more comprehensive tests.

  • Formulating testing strategies: An SDET engages with clients and customers to understand the requirements of the automated tests they design. This understanding helps them create strategies to design tests that can fulfil the needs of an end-user.

  • Compiling and reporting automated results: An SDET design programmes and collects and reports the test results. An SDET interprets the results generated by an automated program or from manual testing.

  • Communicating technical information to clients and customers: Besides communicating with technical staff, an SDET may talk to clients and customers who may not understand technical keywords and terms. They communicate the details of entire development processes in simple and non-technical terms so that a wider audience can understand it.

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Technical Skills Requirements

Employers may expect specific technical skills in an SDET. Since SDETs are knowledgeable both in software development and testing principles, they are likely to possess a variety of skills and specialised knowledge. If you are keen on becoming an SDET, consider developing these:

  • Good understanding and working knowledge of testing principles and methodologies

  • Proficiency in using debugging tools and web applications

  • Knowledge of at least one scripting language to write reusable scripts

  • Knowledge of API testing clients

  • Knowledge of White Box Testing tools and techniques

  • Familiarity with at least one cloud technology platform

  • Familiarity with at least one front-end automation framework

  • Knowledge of versioning tools

  • Familiarity with basic OOP concepts

  • Knowledge of performance testing and security testing

What Are The Additional Skills Required To Become An SDET?

Along with a range of technical skills, an SDET can also develop soft skills to excel in their field. These skills are crucial to keep up their pace of work and to engage effectively with professionals within and outside the software development team. Some important skills for software development engineers in test are:


Companies typically employ fewer testers than developers in a team. An SDET may also participate in stakeholder meetings, create frameworks and tools for their tests, plan testing strategies, identify defects in products and send feedback to the development team. SDETs benefit from being able to multitask.


An SDET may be an expert in a set of techniques and may have specialised skills. They may be often required to work on testing projects that require a different set of skills. Employers expect them to adapt and learn new skills to complete their tasks successfully.

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The role of an SDET is prominent because they design ways to minimise redundancy in manual testing. Apart from automation, they also test products to discover hidden bugs and identify errors in code. The ability to innovate and find new ways to improve testing, productivity and the quality of products is beneficial for an SDET.


SDETs periodically communicate with stakeholders, developers and end-users to understand their requirements and to give feedback. They also act as a channel of communication between product owners and manual testers. The ability to communicate in a clear and logical manner both orally and in a written format helps an SDET complete projects successfully.

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How Is An SDET Different From Manual Testers?

Though the function of both an SDET and a manual tester is to test software created by a development team, their job roles are not exactly the same. Their roles, duties and responsibilities within a project differ depending on the type of testing they do. Here are some significant differences between a manual tester and an SDET:

Duties and responsibilities

Although manual testers and software development engineers in test assess a programme or code's function, the manual tester directly carries out the test. A manual tester may not create an automated program to perform testing. In contrast, an SDET creates automated testing tools tailored to specific cases and designs programs that automatically gather data. They analyse the results of their tests and help developers fix errors in the code.

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Manual testers only test the functionality of a software or an application and focus on individual test-case scenarios. An SDET writes reusable scripts to simplify a manual tester's job. They also create automation frameworks that enable other testers to speed up their processes.

Knowledge and understanding

Compared to a manual tester, an SDET may have a more comprehensive understanding of the software development life cycle and the testing protocols they use. An SDET also requires significant prowess in programming. A manual tester may not require extensive knowledge of the SDLC. SDETs understand the system at a much deeper and more functional level than manual testers.

Extent of involvement

The SDLC requires a software development engineer in test at various stages. This cycle includes the design, development and testing phases. An SDET's involvement in the cycle differs from that of a manual tester, who joins the project only during the testing phase.

Related: 40 Manual Testing Interview Questions (With Example Answers)

Career Growth Prospects For This Role

An SDET who joins a company as a junior tester can improve their skills and experience to rise to the level of a senior SDET, testing manager and then, a test architect or a solutions engineer. As an SDET in a junior role, you may primarily be writing code and creating automation scripts. A senior SDET may coordinate with a larger team to develop automated test tools and frameworks. A testing manager may manage multiple teams of testers. A test architect or a solutions engineer creates frameworks or designs the architecture for a diverse range of projects.

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