In the 17 October issue of Science, three Review articles examine regulatory feedback loops and the insights being gained on signaling through new modeling and lab techniques. In the 21 October issue of Science Signaling, Perspectives look at the role of scaffolding molecules in pathway responses, how pulsatile inputs can shed light on dynamic signaling behaviors, and how advances in chemical approaches are also offering deeper insights. And an original research paper shows how ideas gleaned from the world of digital-circuit engineering can be applied to biological systems.