@freemo First off, a caveat. my role is VERY strange. My title is Enterprise Architect, and I have seen my fair share of code, but I have *never* had a purely programming position, so I might not understand how hiring works.
In any case, my thought...
this seems very fair, but wonder if u might just send everyone the bounty route. If they don't have at least passing familiarity with the codebase, how likely are they to get the job? The toy project seems like it might give a false sense of hope