Postman Interview Questions

Postman was developed to streamline the problems of the API testing process. However, now, it has become one of the most popular collaboration platforms used in developing, testing, and API design. 

Keeping in mind the progress this tool has undergone all these years, many professionals are looking forward to developing their careers with this technology. If you're one from the lot, this post covers some of the latest Postman interview questions for freshers and experienced. Let's have a look ahead.

1. For Freshers 
2. For Experienced 

Top 10 Postman Interview Questions and Answers

1. What is the use of Postman?
2. Can we use the same names in Postman for global variables?
3. Why does Postman mostly use Base64 encoding?
4. What are the different variable scopes that Postman offers?
5. What are Postman workspaces? And what purpose do they serve?
6. In Postman, how will you create random integers in a particular range?
7. What constitutes an HTTP request's fundamental components?
8. In Postman, may global scope variables have duplicate names?
9. What is the purpose of the Postman cloud?
10. Why isn't it better to save your work in the Postman cloud?

Postman Interview Questions and Answers for Freshers

1. What is Postman?

Postman is an HTTP Client-based software application primarily used to test APIs. It allows you to test HTTP requests using a GUI (Graphical User Interface) that may be run and the results checked. It also facilitates API development collaboration among team members by offering a platform for designing, developing, testing, and documenting APIs.

2. What is a Postman collection?

In Postman, a collection is used to organise requests that are related. It aids in the organisation of requests into folders in an organised manner.

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3. What is the use of Postman?

Postman is used for the following reasons:

• To begin, Postman is a free piece of software used to test APIs.
• It may send a variety of HTTP queries (such as GET, POST, PUT, PATCH, and so on) and save environments for later use.
• It aids in the management of the API's end-to-end lifetime, from design to mocking to testing and finally maintenance.
• It has a Runtime Service that aids in the management of API collections, environments, workspaces, and many examples.
• It can easily be integrated with CI/CD solutions like Jenkins.
• It has a lot of community support and provides a lot of documentation.

4. What encoding does Postman support for authorisation credentials?

Postman accepts only Base64-encoded permission credentials. Postman comes with it by default. If we don't want to use the built-in encoding system, we can use third-party websites to convert the credentials to base64 format.

5. Can we use the same names in Postman for global variables?

Global variables have a global scope that is limited to the workspace. As a result, global scope variables cannot have the same names. Local variables can have the same names, but they must be part of different variables.

6. Describe postman monitor

Monitoring is a technique for keeping track of the health and performance of APIs. Postman has built-in monitoring capabilities that help us stay on top of API development and performance. 

Postman's monitors are primarily focused on the operation of collection runners. They run each request in the collection and look at the values in the test scripts. The monitors use the test scripts to validate and track the replies. The reports generated are shared with the developers via emails or alerts in Slack, Hipchat, and other platforms based on our configuration choices.

7. In POST methods, what is a binary form?

The binary form is intended to assist in transmitting data in a format that cannot be entered manually. These options are used for submitting large files in a POST request, such as photos, CSV files, etc. The most straightforward encoding for sending complex data with the request is binary.

8. Why does Postman mostly use Base64 encoding?

Base64 encoding is widely used because it allows data to be transmitted in a textual format that is easier to send in HTML form statistics requests. Another reason we utilise this is that encoding with identical 64 characters is quite reliable in any language.

9. Why is the 304 status code used?

NOT MODIFIED is the 304 status code. In the case of limited GET queries, this is used to reduce the network's bandwidth. In such circumstances, the response body should be empty or blank, and the headers should include information such as the date, location, and signature, among other things.

10. Why isn't it preferable to save work on the Postman cloud?

Because of the required privacy and security, it is not recommended that we store our work on the Postman cloud when working on enterprise-level applications for enterprises. A skilled hacker has the potential to compromise the security of the Postman cloud.

11. What are the different variable scopes that Postman offers?

The following variable scopes are available in Postman:

• Global Variables: Global variables allow data to be shared between many collections, requests, and scripts. They can be found all over the office.
• Environment Variables: These allow us to customise requests for various development settings, such as local testing, stage testing, and production testing.
• Local Variables: These are temporary variables that request scripts can only access. Depending on the needs, they are either limited to a single request or a single collection. These variables are no longer available after the script has finished running.
• Variables in a Collection: These variables are set to be available for all requests in the collection. They are unaffected by their surroundings.
• Data Variables: These variables come from external JSON or CSV files that define the datasets that Collection Runner or Newman needs to conduct the collection.

12. Can the authentication token be reused for many requests?

Yes, it's conceivable. It is possible to create a collection, add all requests with the same authentication token, and then assign the authentication token to the collection. Select the "Inherit auth from parent" option on the Authorization tab to apply this to individual requests.

13. What are Postman workspaces? And what purpose do they serve?

Workspaces are Postman-provided areas/spaces for teams to collaborate on a specific set of collections. It allows you to logically divide requests or collections exclusive to a developer or team, making request administration accessible.

In Postman, there are two sorts of workspaces:

1. Personal Workspace: These workspaces are essential when working on many projects simultaneously and need logical separation between requests to handle them better.
2. Team Workspace: These are designed for group collaboration so that multiple people can participate in testing requests.

By publishing the users' email addresses, we can encourage new users to collaborate on our collections. After accepting the invitation, new users can begin contributing to the workspace by adding or changing requests.

14. What is ScratchPad?

Scratch Pad is a Postman-provided workspace that allows us to operate without relying on Postman servers. It allows you to use some of Postman's capabilities when you're not connected to the internet. The features include creating collections, creating requests, and submitting requests. These are saved locally, and the work is saved into the workspace once you log in.

15. Does Postman give you the option of using the command line?

Postman supplies the Newman command-line tool, which can be used to run any Postman collection. It's a NodeJS-based package that uses Newman Collection Runner to execute collections. It is fully compatible with Postman's Collection Runner, which means it may run assertions, pre-request scripts, and other request scripts tied to the collection's requests.

Newman can be used by following the procedures below:

• Setup Node
• Using the npm command, install the Newman package as follows: npm install -g newman
• Open Postman and export the environment to JSON format to run the collection. Then use the following command in Newman to run the collection:

newman run {{path to collection json}} -e {{path to environment json}}

Postman Interview Questions and Answers for Experienced:

1. In Postman, how will you create random integers in a particular range?

If you want to create numbers in the range of 1 to N, you can do so as follows in the pre-request script:

pm.globals.set('randomnumber, Math.floor (Math.random() N));

We can then utilise this variable in the URL as

{{randomNumber}}

2. In Postman, what is digest auth?

Postman provides the Digest Authorisation method as one of its authorization options. The client sends the request to the API first, and the server responds with a number that can only be used once a realm value and a 401 unauthorised response code. After that, we'll receive an encrypted data array including both the username and password and the previously obtained data from the server. The server generates an encrypted data string from this information and compares it to what was sent to authenticate the request.

This can be done by going to the Authorization tab and selecting "Digest Auth" from the drop-down menu. The fields for both stages of the authentication request are displayed in the Postman window. Based on the data received from the server, the fields required for the second step of the request are auto-filled.

Related Article - What is API Testing

3. What is an application programming interface (API)?

Application Programming Interface is an abbreviation that stands for Application Programming Interface. API stands for Application Programming Interface, and it is a set of routines, protocols, and tools for creating software applications. APIs define how one piece of software should communicate with another.

API stands for Application Programming Interface in basic terms. API serves as a connection point between two software applications, allowing them to communicate. A programming interface (API) is a set of software capabilities that another application can use.

4. What constitutes an HTTP request's fundamental components?

An HTTP request consists of five main components:

1. HTTP methods: A set of request methods used to accomplish a specific action on a resource (GET, PUT, POST, DELETE)
2. URI (Uniform Resource Identifier): Identifies a resource.
3. Version of HTTP (example- HTTP v1.1)
4. Content-type: application/json, Content-Length: 511) Request Headers
5. Payload: This is a Request Body that contains the message content.

5. What is Postman's Basic Auth?

In Postman, Basic Auth is an authentication method that allows HTTP user agents such as web browsers to enter a username and password. Once you enter the login and password, it is paired with the request.

6. Postman accepts authorisation credentials in which types of encoding?

The only codec supported by Postman is Base64. This is built-in to Postman, or you can use third-party websites to convert your credentials to base64.

7. Why does Postman only allow Base64 encoding?

We utilise base64 because it converts data into text and sends it more straightforwardly, such as HTML form data. We can also rely on the same 64 characters in any encoding language.

8. In Postman, may global scope variables have duplicate names?

Global variables cannot have duplicate names because they are global; they exist outside of any environment. The names of local variables can be the same in multiple settings.

9. What is a Postman Collection, and how does it work?

Individual requests can be grouped in a Postman Collection. Simply put, it enables us to categorise requests into folders.

10. What do you mean by "postman monitors"?

Collections are run using the postman monitor. Collections are run until the user specifies a time limit. The user must be logged in to utilise Postman Monitor. Users provide daily/monthly monitoring reports to each other via email.

Related Article - Postman Tutorial

11. What is the purpose of the Postman cloud?

A Postman cloud is a centralised location where businesses can access Postman collections. Work can be stored instantaneously in the Postman cloud after logging in. Anyone on the team has access to data and collections from any location.

12. Why isn't it better to save your work in the Postman cloud?

It is not recommended that you save your work in the Postman cloud since company work cannot be leaked and must remain confidential. If Postman cloud is used, security breaches may occur since Postman cloud requires sign-in. As a result, saving work on Postman Cloud is discouraged, while team workspace is highly encouraged.

13. In a Collection Run, what will execute first?

In a Collection run, pre-request scripts at the Collection level are executed first.

14. What are some of Postman's JS libraries to offer?

GUID, Lodash, Moment

15. What exactly is a GUID?

The term GUID refers to a globally unique identifier. Hyphens separate hexadecimal digits in this format. GUID satisfies the requirement for uniqueness.