So, the problem is this. The myth is about a "10X programmer". No qualification. If you look at hiring discussions, there seem to be a significant number of people in these circles that believe there are programmers who are nearly 10 times as productive as the average (or bottom; this seems to change from poster to poster) at nearly everything they touch. If you don't believe me, read some of the hiring discussions here.

Jessica is not a "10X programmer". Jessica is a "10X $TASK programmer", where $TASK may or may not comprise an entire role. $TASK might even be as large as "web dev" or "enterprise dev". It is nearly impossible to screen for, though, unless someone has directly comparable work experience, where directly comparable includes intangibles like work environment.