I see testing as a partial solution to the more general question - does this thing work. In software product development, someone comes up a problem to which th

I see testing as a partial solution to the more general question - does this thing work. In software product development, someone comes up a problem to which the solution is to build something, someone then build it, someone then test it to make sure it functionally works, then someone test whether they are addressing the right problem. Someone can be same guy or split into different teams. But I duplicated effort in answering the question of "does this thing work"