13. What is API authentication and how does it work?#
API authentication is the process of verifying that an API user has permission to access the data and resources they are requesting. It works by denying or blocking access to servers for unauthorized users when an identity mismatch occurs. For example, if you were to provide the wrong username, password, or another form of credential, then the API would be unable to verify your right to access data within its server.
API authentication is an excellent security layer that prevents cybercriminals from launching attacks on vulnerable systems.
14. What is API testing?#
Interviewers are looking to see if you can recall fundamental concepts and put them into practice when they ask API testing interview questions. Always be brief but descriptive in your answers.
API testing is a software testing strategy that ensures APIs are stable, functional, reliable, and secure.
API testing works by analyzing the business logic, security, application, and data responses.
An API test is generally performed by sending requests to one or more API endpoints and weighing them with expected results.
Some examples include:
- Validation
- Security testing
- UI testing
- Functional testing
- Load testing
- Penetration testing
- Runtime/error detection testing
- Integration testing
- Fuzz and interoperability
- Unit testing
15. What are some advantages of API testing?#
Describing advantages can showcase your critical thinking capabilities, which are helpful on the job. Ensure your answer demonstrates an understanding of when and where to apply a certain aspect of an API in a scenario.
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Convenient: API testing is less time-consuming than GUI testing- which is a software procedure for testing a graphical user interface, due to less code usage. It also offers more efficient and effective test coverage because it allows you to access the application without needing the user interface.
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Language-independent: Because data transfer occurs via XML or JSON, language independence allows users to have flexibility in choosing coding languages needed for automation testing.
This question once again tests your fundamental knowledge of APIs. List the tools you’re familiar with, why you use them, and describe how you’ve used them in the past.
Here are a few examples of popular API testing tools:
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Katalon is a test automation tool that supports SOAP and REST requests
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Postman is used to test REST APIs and provides an interface for making HTTP requests and viewing the response
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SoapUI Pro is used to test SOAP-based APIs
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Apigee can be used to test both SOAP-based and RESTful APIs
17. What are some common bugs found during API testing?#
This question tests the depth of your knowledge of using APIs practically. You should explain your understanding of a few situations where you encountered bugs during testing.
A few common bugs found during API testing include:
- Missing or duplicate functionality
- Inconsistent error handling and detection
- Security issues
Unexpected error codes e.g wrong HTTP status codes
18. What is API documentation?#
Turning to API documentation when you’re working with an unfamiliar API should be one of your first steps. You can explain the steps of your process to your interviewer to demonstrate resourcefulness and independent problem-solving skills.
API documentation is technical content that describes the API in detail. It includes everything you need to know about the API, from effective integration to updates to the API lifecycle and test design and coverage. It also includes a collection of resources, tutorials, and reference guides that enable developers to install and use an API.
19. What is Runscope?#
Interviewers will ask this question to test your fundamental knowledge of API concepts. Being brief and clear in your response.
Runscope is a web application used to monitor, debug, and performance test web service APIs. It provides an accessible interface and backend services to test APIs to ensure they work optimally.
20. How are API testing and unit testing different?#
API testing and unit testing are different functions. It’s important to be able to distinguish the two
API and unit testing are different in the following ways:
