This article discusses the design considerations for building video calling products using Daily.co's API. The author highlights the importance of designing a user-friendly interface, including core components such as call controls, local camera feeds, and remote video grids. They also emphasize the need to consider secondary components like contextual UI, modals, and notifications, which provide important information to users. The article aims to provide guidance for developers who want to integrate Daily.co's API into their products, offering a framework for building custom UI that balances user experience with feature requirements.