Lately I have been helping customers find talented developers. As the topic of many books, courses, web sites and numerous other sources (many of which I have read or used) it is a problem that I find keenly interesting.
There are of couse many, many ways to look at it, but I think I have found the single most important strength not just for technical talent. So take this as advice for your own advancement or as the thing to look for and test for when you are hiring. The key strength is to be able to accept feedback and objectively recognize it for truth when it is true and then have the strength of character to actually try to work to improve as a response.
It sounds easy, but it is not. It is also very much at odds with being an ego maniac (in other words those people can’t do it). If someone passes this test then the sky is truly the limit, they will be able to improve, move up the ladders of responsiblity and will likley only be limited by the strength of their intellect.
Try it yourself sometime by asking someone for honest feedback and see if you can act on it. Repeat.