This probably wouldn't work unless you are an extremely exceptional candidate (ex: a leader in the field, major contributor to an open source project they use i

This probably wouldn't work unless you are an extremely exceptional candidate (ex: a leader in the field, major contributor to an open source project they use internally, etc). Most of the time employers have the upper hand since there are a number of people applying to a single position. So if a number of qualified candidates apply, and one hands them an "employer challenge", their resume will be thrown in the trash.