Hanami
A flexible framework for maintainable Ruby apps
...Each component—like the router, model layer, or view rendering engine—can be used independently, which gives developers flexibility to build lean applications. Hanami promotes immutability, plain old Ruby objects, and minimized global state, which makes codebases more maintainable and testable. It supports multi-application setups within the same project, making it well-suited for larger service-oriented architectures. The framework is designed to provide Rails-like productivity while encouraging more explicit architecture and performance-conscious choices.