* How interesting are those projects generically and in the context of what I would need this developer to do?
* Are these projects actually used by anyone? Are there pull requests, etc?
* Does the developer actively keep working on existing projects or move around? I.E., are these learning vs hobby vs commercial?
* How is their readme? Does it exist? Is it sufficiently complete to convey meaning?
* How is the code organized? Is it reasonably laid out? Do they make use of third party packages and tools? Does it seem like they are re-inventing the wheel?
* Does the code work?
* Is the language chosen the right language for the job? Are they using idioms of that language or more generic ways of expressing loops, vsriables, etc.?
* How extensible is their design? Does it feel krufty or is it a pleasure to read?
* Is the code novel? Are they re-inventing the wheel or are they actually fulfilling a need?
* Are their projects wide and varied in scope and tools?
Those are a few things off the top of my head. Not an exhaustive list.