Interaction Design as a practice places designing for user behavior at the center of the design activity. At its lowest level, Interaction Design looks at the request-response mechanisms and controls - the microinteractions - that make up the fundamental building blocks of technology. As we increase the scale of our efforts, Interaction Design shifts in focus from microinteractions to screens and tasks; screens and tasks to activities; activities to services; and services to interconnected systems. At the same time, the toolset and perspective of the Interaction Designer needs also to shift. This talk will look at examples of this change in perspective as we design at different scales of interaction, and the accompanying change in method and skill set needed to successfully navigate between them. Finally, the talk will also look at how our definitions of 'high-level' and 'detail' shift in line with the scale of our work. The underlying message of the talk is this: the most successful interaction designers simultaneously operate across scales, balancing high-level thinking with detail, and moving seamlessly between the two.