I see wonderful symmetry here. There are TrendyCos (hot startup unicorns), BigCos (established companies like google or amazon or microsoft) and UnknownCos (not in the limelight so there is not much information about them). Likewise there are TrendyDevs (hotshots who produce one heavily github-starred framework after another), BigCoDevs (multiple years of experience at one of the BigCos, probably were responsible for…
There's no magic to it at all. Have every candidate work on programming problems related to the work you do at your company. Have every candidate work on the same problems, and let them do it from home. Build and iterate on a rubric for grading those challenges. It is amazing to me that almost nobody does this, but: almost nobody does this. They have programmers write code on a whiteboard, or on some whiteboard-codin…
My last job search wasn't typical (I thought of starting a consultancy, so didn't search for a job per se), but one before that showed to me that it's exactly what people do. A company that was looking for a guy to write mobile SDKs asked me to build an Android app with embedded webview and animate html stuff with JS based on gyro movement. A slot game company asked me to build a minimalistic slot game from scratch (thanks to them, I have a clean minimalistic and complete game on github now). Another game company asked me to build a small endless shooter — and I ended up being the only candidate who moved texture offsets instead of actually moving game objects to infinity.
Each of those tasks took from 4 to 8 hours, and 2 of those got me an offer. And of course, I used the same method when I consulted others on hiring decisions or hired people myself. So, based on personal experience, companies do that, and it works.