I mean, maybe my management and hr is filled with racists and sexists, but my gut reaction is they seem like pretty progressive folks. I think the pipeline is messed up much, much earlier.
This is a tricky question for senior/principle software people, but perhaps as a proxy, we could look at the number of new grads at the Bachelor's, Master's and PhD levels that are employed {six months prior, one month prior, one month after, six months after} graduation, as broken down by gender and ethnicity.
For example, if 95% of women are hired by one month before graduation day, that would suggest that we need to be looking at an earlier point in the pipeline (educating parents, additional funding at the elementary or high school level, teaching boys how to not sexually harass girls in middle school, etc.). On the other hand, if 20% of women are hired by six months after graduation day, then maybe that means there's something funny going on during the hiring process.
If they dig deep and analyze the race diversity of women in tech, I bet the data would be more striking.
Google's description of what they are doing about diversity seems to indicate that they see exactly that as the problem -- most of their actions discussed are about growing the pool of qualified candidates in underrepresented groups.