Explore effective strategies for building cross-platform mobile applications using Xamarin in this 58-minute conference talk by Filip Ekberg at NDC Conferences. Learn how to optimize code sharing across different mobile platforms using C#, focusing on both good and bad practices. Discover techniques to overcome device fragmentation, implement abstraction, and utilize patterns such as IoC containers and service locators. Examine the pros and cons of Xamarin Forms, including embedding options for iOS and Android. Dive into dependency injection, messaging centers, and the MVVM pattern with practical code examples. Address challenges like ahead-of-time compilation, package management, and app size optimization. Gain insights on when to use Xamarin, how to handle native compiled binaries, and strategies for successful mobile app development.