I’ve suggested binary distribution as part of a black box exercise in the past. Locking down the source and being able to change details for each candidate would mean solutions posted online would not help.
Unless you're crafting some revolutionary problem for each candidate, changing details won't matter much.
I’m talking about a take home code challenge. It’s unreasonable to have someone to record a video that could last an hour or more. And I’m not gonna sit and watch that.