API Federation is a crucial part of modern API management that provides a unified interface for external users while promoting flexibility and agility within the internal service ecosystem. It involves designing APIs with end-users in mind and treating internal APIs as public ones, ensuring they are well-designed, secure, and scalable. Adopting a user-centric approach when designing APIs is essential to understand the needs and expectations of API consumers. The language you choose to code your APIs in can impact developer productivity and flexibility within the service ecosystem. Exploring alternatives like gRPC can offer stronger type safety and more efficient communication, allowing organizations to choose the most suitable approach for their specific use cases.