I don't mean to propose that people spend their off hours writing work samples - that's unreasonable for all the reasons you've given and more. What I mean to

I don't mean to propose that people spend their off hours writing work samples - that's unreasonable for all the reasons you've given and more. What I mean to propose is that we dramatically alter the current on-site interview process used by most companies. Instead of 5-7 interviews, consisting of 5-7 independent but ultimately equally contrived algorithms questions on a whiteboard, use the several hours you have the candidate to produce real, working code that reflects the work that your company does. Which is to say, this requires no more time commitment than the existing interview processes at typical tech companies. If the work your company does is deeply algorithmic, this will be reflected in the work sample produced via this process. If the work your company does is more heavily UX-oriented, this will be reflected in the work sample produced, also. Instead of "over the course of a full-day on-site round of interviews, candidate produced several short snippets of hand-scrawled code solving various CS textbook problems, which we will now use to infer general engineering ability"... ... you can say "over the course of a full-day on-site round of interviews, candidate designed and produced a module of code that does [X small thing that company does], which can be assessed with the same rigor and methodology we already apply to our existing work and employees"