I would say a solid understanding of the fields that development most commonly intersects with. Typically business (including politics), product, networking, operations, and security. You don't need to be an expert but you do need to be able to carry on intelligent conversations at the intersection points.
You don't need to be an expert but you do need to have a firm grasp of the basics.
You don't need to be an expert but you do need to have a firm grasp of the basics.