Love linking lines? Join me in considering the humble arrow as both a programming problem and a user experience challenge. In this talk, I'll present the many complex problems and solutions that I've encountered when working with arrows in my open source library perfect-arrows and later in tldraw (tldraw.com). With a narrow scope and plenty of animations to guide the way, we'll look at intersections, arrow heads, arrow head angles, and all of the different user interface issues behind authoring and adjusting arrows between shapes, other shapes, and points.