Which of the following describes the main capabilities of medium-level technology delivery?

Medium-level technology delivery primarily focuses on the capabilities that enhance the reliability and efficiency of API interactions and their integration with backend systems. The correct choice emphasizes fault tolerance in API invocation, which means that the system can handle failures gracefully. This is essential in ensuring that services remain available and perform as expected, even under conditions of partial failure. Additionally, backend system integration is crucial because it enables APIs to connect seamlessly with various underlying systems, ensuring that data flows correctly and business operations can continue without interruption.

While API design and hosting are fundamental components of API management, they are usually considered part of the initial setup process rather than ongoing capabilities associated with medium-level delivery. Consumer engagement strategies focus more on understanding and managing user interactions rather than addressing the technical infrastructure or reliability of services. Lastly, while API analytics and reporting are important for monitoring and understanding API usage and performance, they do not directly address the core functional resilience and integration aspects that characterize medium-level technology delivery. Thus, the emphasis on fault-tolerant API invocation and backend integration aptly captures the essence of the capabilities at this delivery level.