Explore Twitter's open-source Finagle library for building high-performance, scalable distributed applications in Scala. Learn about this RPC framework built on Netty, its ecosystem including Finch and Finatra, and how it facilitates the development of microservices. Discover the key concepts of Finagle, including services, filters, protocols, and service discovery. Gain insights into why Finagle is a powerful choice for creating robust, asynchronous, and multi-protocol systems, and how it can be leveraged to build and scale applications composed of heterogeneous services.