Generally the hiring pipeline at Google does not involve a hiring manager until after the individual has been accepted. There are exceptions for special roles and people, but for the software engineer case, we require that someone be generally competent across the board. Once they're in, then their specialties and interests factor into what team/project they start on.
By generally competent across the board, you mean adept in a variety of disciplines, but only within the general discipline of Software Engineering. Of course, this covers a lot of ground, from networking to kernel development, to web frameworks, database system (RDBMS and NoSQL), and even old-school assembly...
Or no? Perhaps you look at the fundamentals of algorithms, such as types of sorting, binary data operations, that sort of thing...
Either way, many people will not be able to know enough across the board to make the cut, who in one or two particularly focused areas may be quite talented, and there may be people who, having spent all their waking hours in the deep study of bits and bytes, pass all such tests with flying colors and who, once in the company, poison the well of goodness because of their inability or unwillingness to adapt to rapidly changing surroundings, because of their inability to endure tenaciously under, shall we say, difficult managerial arrangements, and because of their inability to genuinely care about the welfare of their peers, Google customers and clients, and Google investors, both in word and deed?
Perhaps this is not what happens, but, from the outside, as far as I can see (and I remember the pre-google days of Lycos, HotBot and metacrawlers) Google the Company behaves as one would expect a talented yet socially awkward and uncouth twenty-something; brash yet caring, uneven in his affections, vacillating between opposites, such as standing up for freedom and privacy one year, then chucking freedom and privacy to the wind the next for a sizable windfall. This person can charm yet irritate, seem brilliant in one area but somewhat novice in another.
This is how I see Google, and I see very little, standing on the outside as I am, that leads me to believe that there sill be change for the better anytime soon.
