The safest way to hire is to find someone you've worked with before. Unfortunately, it perpetuates bias.
NY Times: Karina Lake of Stitch Fix on Building Diverse Teams, 2018-Jun-1 by David Gelles
One of the biggest challenges standing in the way of diversity and equal opportunity for people is the way that people build founding teams. People tend to bring on my buddy from this thing and then my buddy from that thing, and it’s like, “You’re just kind of bringing the same people that you’ve worked with back together, getting the gang together again to found another company.” That just creates this circle of capital raising that I think is not healthy, and I don’t think people are looking at the whole world and saying, “Who are the best people for these jobs?”