I think that the secret ingredients are this:
- Open source projects (the more GitHub stars, the better).
- Tech blog (the more followers, the better).
- Experience working for at least one hot Silicon Valley startup.
- Experience working for at least one large corporation.
- Momentum: Proof that your career has been going upwards recently, not downwards or stagnating.
If you're older, they may also want:
- Proof that you're adaptable and open to criticism.
Unfortunately, it's extremely competitive and companies are obsessed with getting "The best" and they will not admit to themselves that they don't actually know what that means.