In Agile teams, QA/Testers are typically responsible for conducting API testing. Developers focus on coding, Product Owners on defining user stories, and Scrum Masters on facilitating the Agile process. QA/Testers ensure the quality of the software by testing various aspects, including API functionality, performance, and security.

When dealing with numerical inputs in API testing, applying Boundary Value Analysis to the minimum and maximum values is crucial. This approach helps reveal hidden bugs that may arise at the edges of the accepted input range. By testing both the lower and upper bounds, testers can ensure the reliability and correctness of the API's numerical handling.

RESTful APIs utilize standardized HTTP status codes for error reporting, making it easier to understand and handle errors. In contrast, SOAP APIs primarily use HTTP status codes, but they may also define custom error codes for specific scenarios.

Mocking APIs helps simulate the behavior of external services or components, allowing developers to test their code in isolation and ensure proper integration without relying on the actual services.

Measuring throughput is crucial when testing for peak load, as it reflects the maximum number of requests an API can handle efficiently. Throughput indicates the system's processing capacity under heavy loads, providing insights into its scalability and performance.

OAuth 2.0 introduced a shift from signatures to tokens for better scalability and simplicity. It relies on access tokens rather than cryptographic signatures for security.

Load testing is essential for evaluating the performance of an API under various levels of load. It helps identify bottlenecks and weaknesses in the system when subjected to sustained use and heavy loads.

In a CI/CD pipeline, API tests are typically executed after the Deployment stage. This is because, during the Deployment stage, the application is deployed to a testing environment, allowing for comprehensive API testing to ensure the proper integration of components. API tests at this stage help catch integration issues before they progress further in the pipeline.

RESTful APIs commonly use JSON for data exchange, providing a lightweight and easy-to-read format. SOAP APIs, on the other hand, typically use XML for data exchange, which is more rigid and structured.

Data-driven testing, in the context of API testing, assists in maintaining scalability by enhancing reusability. As the complexity of the API increases, using data-driven testing allows the same set of test scripts to be reused with different sets of data. This promotes efficiency and reduces the effort needed to handle varied scenarios. By parameterizing the inputs, the testing process becomes more adaptable and scalable, ensuring effective API testing in dynamic environments.