Discuss the principles of RESTful API design and how they ensure scalability and maintainability in web applications.

RESTful API design is based on principles such as statelessness, uniform interface, resource-based URLs, and standard HTTP methods (GET, POST, PUT, DELETE). These principles promote scalability by allowing stateless interactions, making it easier to scale servers horizontally. Maintainability is ensured through a clear and consistent API structure, making it easier for developers to understand, use, and extend the API without breaking existing functionality.