Explore the transition from Objective-C to Swift in this 40-minute conference talk from Strange Loop. Delve into the complexities of the Swift-Objective-C bridge, examining its impact on language design and engineering challenges for developers adopting Swift in existing projects. Learn about the weight of the Objective-C bridge in Swift, including added complexity and elements that persist or disappear when Objective-C is not in use. Gain practical insights from real-world experiences, covering features that caused the most friction with large existing codebases, strategies for smooth gradual adoption, and the tangible benefits observed in practice. Led by Andy Matuschak, mobile engineering lead at Khan Academy and former Apple UIKit team member, this talk offers valuable perspectives on software architecture, platform evolution, and the nuances of language interoperability in iOS development.