One of the things that’s helpful about having been at Yahoo more than a few years and having multiple roles during that time is that it provides lots of opportunity to meet lots of people and figure out what they’re good at.
As a by-product, I’ve managed to build up a list of people who constitute my "dream team." These are the people that I wish I could take with me when I move into a new group and/or role. It’s rare that you can get ’em to move since these are also the people who are often quite happy in their roles, but it never stops me from trying.