Modularity has been around for a long time now; concepts like object-oriented programming predate the Web by a long shot. So why the sudden interest in pattern libraries and design systems on the Web? We’re tasked with creating experiences that look and function beautifully across a dizzying array of devices, browsers, screen sizes, network connections, locales, and environments. That’s a tall order in and of itself, but once you factor in team members, clients, stakeholders, and organizational quirks, things start looking downright intimidating. Style guides and design systems provide solid ground for us to stand on as we tackle this increasingly-diverse Web landscape. This session will discuss considerations and best practices for creating and maintaining effective interface design systems.