Anecdotally speaking, in the last 2 years, I've seen 3 ex-Twitter (as their most recent position) people apply, and none of them made it passed the second phone interview, which was the first real technical one.

I didn't do the interviews myself, but I watched them, and I was very unimpressed with the applicants.

I can say this about most (70%) Amazon people too... (and am in Seattle, so we see a lot of them).