To become a successful SDET, one should be involved in both the development of application as well as in testing of the software developed. SDET plays an important role in both the Software Development Life Cycle as well as Test Life Cycle. SDET engineer plans, designs, develops, optimizes as well as test the code using automation.
SDET can think about the probabilities the application code can fail and design his test framework accordingly to ensure robustness of the product. SDET needs to understand the complete flow of the code about how it interacts with all other components and can write his own code for creating specialty test tools for automation.
SDET should possess excellent debugging skills in order to find out the reasons behind the failure of test cases, inefficient code, memory leakages etc., in order to improve the quality of the code. SDET should be able to create a report of all his testing activities which will help in tracking the entire task.