Every hiring mistake I have made — and there have been several I still think about — was a decision made on capability while ignoring something I had already noticed about character.
Not noticed vaguely. Noticed, named privately, and then argued away because the candidate was strong on paper and the vacancy was painful.
The three signals
How they speak about their last employer, when they think the interview has relaxed. How they treat the person who brings the tea. Whether they can describe a failure in specific terms without arriving at a version in which it was someone else’s fault.
None of these is decisive alone. Together they have been more predictive, in my experience, than any qualification on the page.
The uncomfortable corollary
You are not going to fix it. I spent years believing that a good environment would reshape someone, and occasionally it did, at a cost to everyone around them that I had not counted.
Hire slowly for the things that take years. Train quickly for the things that take a quarter.
