That seems like something you could build. There's a handful of YC companies working on that.
I don't think FANG companies are likely early adopters of that. They are all relatively conservative with hiring. Navigating the organization to find an internal champion who's incentives are aligned seems really tough. Internal established recruiting teams seem disincentivized to use a 3rd party certification. Using that might reduce the number/importance of the internal recruiting team.
Knowing more or specific technologies isn't what makes someone a good engineer.
Practice identifying problems, taking full ownership of them and fully thinking through and delivering solutions.
This is way easier if you find a problem that you're interested in.
If you're not able to sink your teeth into any good problems, at least pay attention to people around you who do this well so you can copy them in the future.
WA seems large enough that the security community would put in that effort periodically.