This task is beyond most recruiters' skill sets to do properly. Most recruiters are also paranoid about any level of direct interaction, since both candidate a

This task is beyond most recruiters' skill sets to do properly. Most recruiters are also paranoid about any level of direct interaction, since both candidate and interviewer have significant financial incentives to cut them out of the deal, so you'll have to deal with (and work around) that fear. A five-minute programming exercise that you spend more than 5 minutes designing, that you grade yourself, will be about the most you can do before you start turning off qualified applicants, at least at this early stage. If I want to spend 3 hours on a programming challenge with no guarantee of payment, I can certainly come up with more enjoyable ways to do so where I don't get constant reminders that I'm taking too long. The best time for the programming challenge comes after the initial "does this person look like they fit into our organization?" set of interviews. Those interviews not only screen out a large percentage of your pool, but also sells your organization to the applicant, incentivizing them to take longer to get the job.