[cja23]

1. Technical competence: the candidate is unable to satisfactorily answer even the most basic questions about 1 or more of the technologies/skills listed on their resume.

2. Candidate ambitions / Job mismatch: this goes both ways. I have rejected candidates that were clearly just looking for the paycheck and would likely do the minimum necessary to not get fired. I have also rejected candidates that wanted to do a lot more than the position required and would likely get bored and move on quickly. (For the latter, I always try to find another position that would be a better fit, even if it's outside my group, company, or even industry.)

3. Culture/Team mismatch: this is the last, and rarest reason to reject a candidate, and is only considered if they passed the two above hurdles. If the candidate's work/communication styles don't seem like they will mesh well with the existing team, this is sufficient to reject the candidate, although my team needs to feel pretty strongly about this incompatibility.