Or simply that they have significant bias in their interview process for selecting candidates with strong interview skills. At that point it’s tautological—if you only select people who ace interviews then you’ll have a bunch of people who ace interviews.
Author here. We didn't publish a histogram showing how many users we have from each company, so I guess you'll have to trust me on this one. Dropbox has waaaay fewer engineers on interviewing.io per capita than some of the other companies... many of whom didn't make the top ten list.
In our experience, they're quite good at retaining talent.
it's possible. we did see statistical significance when comparing dropbox to others despite the relatively smaller sample size. but yes, that is possible.