What does Software Engineer in Test do?
They write code to examine Software Engineers' code. A great deal of times they create automated examination devices. AFAIK, Google, Microsoft and also various other large software program firms work with a great deal of SETs.
Examination designers make use of 3 sorts of screening approaches which are called black box, white box and also grey box screening.
Short solution: SETs (or SDETs as we call them at MS) examination well past what can be done by unit testing (assimilation, performance, range, integrity, etc), and also write programs, devices, and also automated examinations to assist in the initiative. The duty is fairly comparable at Google.
Longer solution: I've covered the duty (both straight and also indirectly) on my blog site. Start with this post on jobs, or look the website for SDET.
Longest solution: Read my book.