Ultimately employment is a market. You're expecting something in exchange for some money. Your objective is to get as much of "something" for the least amount

Ultimately employment is a market. You're expecting something in exchange for some money. Your objective is to get as much of "something" for the least amount of money. The candidate's objective is to get as much money for the least amount of "something". Junior candidates are more flexible on this as they might do it for the passion of the tech or to make a name for themselves but seniors already have a "name" and no longer need to work for "exposure". Your current situation seems to be that your competition offers a better deal than you do - employees manage to find other places where they can either get more money or get the same money you're offering for much less "something". That "something" includes the overhead of the interview process such as the tech test, etc. In short, either offer more money or demand less "something" and make it known. 4-day work week, flexible working hours, no on-call, etc. In addition, you're asking for specialized skills which means you need to consider markets beyond employment. If your prospective employee can make the yearly salary you're proposing in a 3-month consulting gig, there's no reason for him to even consider your offer. You mention that most applicants dislike the specialization you're asking for - maybe because those who like it don't even apply, potentially for the above reason.