A software development engineer in test (SDET) participates in the entire software development cycle. They both develop and test software. Essentially the position is two professions combined into one. The demand for this role has greatly increased as companies have started to look for multifaceted I.T. professionals and have started to look for ways to decrease the size of the IT department.
To excel in this role, you will need a very strong software development background as well as a testing background. This sample resume shows this very effectively.