API-First Development prioritizes designing and developing the API as the foundation of the entire architecture, treating it as a product in its own right. This approach is different from traditional methods where the user experience comes first, and the API is developed reactively to support that experience. By doing so, an API-First approach allows for faster development, scalability, and integration with multiple developers and teams. It requires extra planning and collaboration between stakeholders but pays dividends in the long run by providing a solid foundation for the entire software system, enabling innovation, collaboration, and interoperability. To get started, designers and developers should create an API Spec File, which serves as both blueprint and documentation for the API, and leverage tools like code generators to streamline development and integration.