Yes, but is cuda going to keep its edge 10 years down the line? Do I want to hardcode my algorithms so tightly with today's cuda APIs? Can there be better more generic primitives that are agnostic of propitiatory cuda APIs but would support it as backend without too much perf hit?
If you want performance then yeah. If you are after hypothetical performance in future which may not even materialise, then the choice is yours. Everyone knows where the sensible ground is. Which, unfortunately, is CUDA only
AMD has a search and replace library that's API compatible with many cuda functions now. It hasn't caught on yet, but if they release decent hardware soon, it might.
The bigger issue is you restrict your hiring pool to the set of people who aren't currently employed somewhere that won't allow that kind of moonlighting, etc.
It works, until your company gets big enough, and then it doesn't work anymore.
One of the main reasons that interviews stick around is because they allow for a much larger applicant pool.
A larger applicant pool, AND because they are a commitment device.
As a candidate, I know that the company is burning roughly the same amount of engineering hours interviewing me as I am burning interviewing them. So it's an honest signal that they are at least somewhat serious.
For comparison, one problem with take-home exercises as a first step, is that (especially good) candidates will wonder whether it's really worth their time when their work might just go into the round file straight away.
I don't like /r/programming either but some of the smaller programming subs are ok.
For example /r/cpp has moderators from the actual C++ standards committee.
In general I wish there's a better way to stalk where these experts hang out. For example at one point /r/machinelearning was pretty good but then the famous researchers left and it's hard to track the diaspora (I think those discussions ended up moving to twitter)
started browsing some of the smaller collaborative reddit communities like /r/ProgrammingPals. It's been a cool way to find other devs to collaborate with.