When a server is temporarily unable to handle requests due to overloading or maintenance, it should return a 503 (Service Unavailable) status code. This informs clients that the server is temporarily unable to process the request and suggests trying again later. A 404 status code indicates that the requested resource is not found, and 302 is a temporary redirect. A 500 status code is a generic server error.

Data partitioning in API testing with large data sets impacts performance positively. It allows parallel processing, reducing execution time.

In a banking system, security and standardized operations are paramount. SOAP APIs provide a strict protocol for communication, ensuring reliability and security. RESTful APIs, while widely used, may not enforce standardized operations to the same extent. GraphQL and WebSockets may introduce unnecessary flexibility and potential security risks.

Mock services simulate external dependencies, allowing API scripts to run in controlled environments. This helps in isolating the testing scope, ensuring reliable and repeatable results. It also facilitates testing scenarios that may be challenging to reproduce with real services.

Microservices typically communicate using asynchronous communication, allowing them to function independently without directly relying on each other's real-time responses.

In tools like Postman, Collections serve the purpose of grouping related requests together. They allow users to organize and manage their API requests efficiently, making it easier to execute and maintain a suite of requests for a specific use case or project.

Continuous Testing in CI/CD is a crucial practice that enables the early detection of defects in API integration. By continuously testing the application throughout the pipeline, teams can identify issues early on, preventing the propagation of defects to later stages. This practice ensures the reliability and stability of the API integration process.

Semantic versioning (SemVer) follows the Major.Minor.Patch format, where the major version is for backward-incompatible changes, the minor version for backward-compatible additions, and the patch version for backward-compatible bug fixes. This approach helps developers understand the nature of changes at a glance.

SOAP APIs are better suited for handling stateful operations as they support features like sessions and transactions. RESTful APIs, on the other hand, are stateless by design, making them more suitable for stateless interactions.

The response time is a crucial metric for understanding the performance of APIs in production. It measures the time it takes for an API to respond to a request, directly impacting user experience. Monitoring and optimizing response time are essential to ensure efficient and reliable API performance in a production environment.

Equivalence Partitioning widens test coverage by categorizing input values into equivalence classes. This ensures that representative values from each class are tested, covering a diverse range of scenarios. As a result, API testing becomes more thorough and comprehensive, detecting potential issues across different input sets.

Frequent changes in API specifications can significantly increase the complexity of API test automation. Test scripts may need frequent updates to adapt to changes in the API, impacting the stability of the automation suite.