Armeria is an open-source framework for building microservices. Our teams have used it to build asynchronous APIs, and we quite like the approach to address cross-cutting concerns, like distributed tracing or circuit breakers, via service decorators. The framework includes port reuse for both gRPC and REST traffic among other clever design choices. With Armeria, we can incrementally add new features in gRPC on top of an existing codebase in REST or vice versa. Overall, we find Armeria to be a flexible microservices framework with several out-of-the-box integrations.