Difference between Software Test Engineer, Test Automation Engineer and Software Developer in Test (SDET)

The IT industry still views testing as a job that anyone can perform with minimal technical skills. A quick search on a leading recruitment site has a number of advertisements for Testers with requirements similar to the following:

At least a few years of experience as a Tester or in a Test Analyst role with demonstrated experience in planning and executing functional, systems and regression tests.

Excellent written and verbal communications skills will be a must for this role – the right candidates must be able to develop clear and concise test cases and test scripts

Some previous experience using Test Director or Quality Center – any exposure to automated test tools (particularly QTP) would be a benefit

Experience of various software testing approaches and SQL in order to extract data for tests.

A methodical nature and high levels of attention to detail.

Typically, no programming skills required, no industry-specific knowledge, just years of testing experience, good communication skills and some experience with test tools.


What is an SDE/T?

An SDE/T is one of the common, technical testing roles at companies such as Microsoft.

Software Design Engineer in Test, Tests and critiques software components and interfaces in more technical depth, writes test programs to assure quality and develops test tools to increase effectiveness.

Generally, SDE/T’s use the same tools, knowledge, and experience, as all the other “developers” on the project. The key difference, however, is they have a different focus and have different goals. However, we aren’t any less capable of writing code that the “developers” on the project.

Software Test Automation Engineers (STAE’s) are more specialized roles that typically is a less technical version of an SDE/T as they focus on automation using off the shelf tools like QTP. So the key difference between an STAE and an SDE/T is that an Automation Engineer normally uses tools, and an SDE/T writes them as he needs to to get the job done.


Should SDETs perform manual testing activities?

Does the SDE/T perform manual testing? : well they CAN, but normally DON’T because they will write tools instead.

Are SDETs responsible for finding issues in the product or to create and maintain the test automation code?


Any tester that is not finding issues regardless of role is not a tester. They are a tool developer. So yes, they need to find bugs.


Do STAE and SDET require application domain knowledge or they just have to automate manual testing scenarios provided from different people?

They shouldn’t require it as a prerequisite, but they should be required to develop it as they automate. If they don’t then

  1. a) they are not testers and/or
  2. b) they won’t be effective.

Do the STAE and SDET only write automated verification scripts?

No. They need to do everything a tester does, plus build or use testing tools. Their main focus will be on writing automated checks, but they could also be generating test data, building test process tools, test harnesses, performance testing, security testing etc.


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