20 AWS Cognito Interview Questions and Answers

AWS Cognito is a user identity and data synchronization service that helps you securely manage and synchronize app data for your users across devices. If you’re applying for a position that involves AWS Cognito, you can expect to be asked questions about your experience and knowledge of the service. In this article, we’ll review some common AWS Cognito interview questions and how you should answer them.

AWS Cognito Interview Questions and Answers

Here are 20 commonly asked AWS Cognito interview questions and answers to prepare you for your interview:

1. What is AWS Cognito?

AWS Cognito is a user identity and data synchronization service that helps you securely manage and synchronize app data for your users across their devices. With Cognito, you can easily create unique identities for your users and synchronize their data across devices and apps.

2. How do you use Amazon Cognito to sign-in users in a mobile app?

You can use Amazon Cognito to sign-in users in a mobile app by using the Amazon Cognito Identity SDK for iOS and Android. This SDK allows you to integrate Amazon Cognito with your app to provide a seamless sign-in experience for your users.

3. Can you explain what the control flow of a typical user authentication process looks like in AWS Cognito?

The control flow of a typical user authentication process in AWS Cognito looks like this:

1. The user enters their credentials (username and password) into the Cognito login page.
2. Cognito verifies the credentials against the user pool.
3. If the credentials are valid, Cognito generates a JSON Web Token (JWT) and sends it to the user.
4. The user then uses the JWT to access the AWS resources they need.

4. What are some common scenarios where AWS Cognito can be used?

AWS Cognito can be used for a variety of scenarios, such as providing user authentication and authorization for mobile and web applications, managing user identities in the cloud, and providing temporary credentials for accessing AWS resources.

5. Is it possible to add support for Federated Identity Providers (like Facebook, Google, Login with Amazon etc.) using Cognito? If yes, then how?

Yes, it is possible to add support for Federated Identity Providers using Cognito. This can be done by using the Amazon Cognito Identity Provider to connect to the provider of your choice.

6. What’s the best way to manage permissions when accessing an object stored on S3 while using Cognito?

When using Cognito to manage permissions for accessing an object stored on S3, it is best to use IAM roles. IAM roles allow you to granularly control access to specific resources, and they can be easily assigned to and revoked from users as needed.

7. Can you explain what the “Remember me” feature does in AWS Cognito?

The “Remember me” feature in AWS Cognito allows users to stay logged in to your app for a period of time, even if they close the app or their device. This can be useful for users who want to have a seamless experience when using your app, and don’t want to have to log in every time they open it.

8. How do you create a login identity provider using Cognito?

You can create a login identity provider using Cognito by creating a user pool and then adding an identity provider to that user pool.

9. How do you integrate Cognito into your iOS application?

The easiest way to integrate Cognito into your iOS application is to use the AWS Mobile SDK for iOS. This SDK will handle all of the necessary authentication and communication with Cognito on your behalf. All you need to do is provide it with your Cognito credentials and it will take care of the rest.

10. What types of data can be imported into Cognito?

You can import user data into Amazon Cognito from a variety of data sources, including your own user database, social identity providers such as Facebook and Google, and enterprise identity providers such as Microsoft Active Directory.

11. Can you explain what federated identities are and why they are important?

Federated identities are a way of allowing users to sign in to multiple applications using a single set of credentials. This can be important for a number of reasons, including reducing the number of passwords that users need to remember, and making it easier for users to access the applications they need. Federated identities can also help to improve security, by making it easier to track and manage user access.

12. What are the various ways in which you can distribute Cognito IDs to end-users?

There are three main ways in which you can distribute Cognito IDs to end-users:

1. Through a user pool: A user pool is a user directory that you can create and maintain within Cognito. Users can sign up for and sign in to your web or mobile app through the user pool, and you can use the user pool to manage permissions and access control for your app.

2. Through a hosted UI: A hosted UI is a web page that you can host on your own web server or within your app. It provides a ready-made sign-up and sign-in experience for your users, and you can use it to federate users with a user pool.

3. Through an identity provider: An identity provider is a third-party service that you can use to sign up and sign in users. Cognito supports federating with social identity providers such as Amazon, Facebook, Google, and Twitter, as well as enterprise identity providers such as Active Directory and LDAP.

13. Can you give me some examples of applications that make heavy use of Cognito?

Some examples of applications that make heavy use of Cognito would be social media applications, online banking applications, and online shopping applications. All of these applications require users to login in order to access their account information, and Cognito provides a secure way to do this.

14. What is the difference between authenticated and unauthenticated access in Cognito?

Authenticated access in Cognito requires that a user be signed in before they are able to access any resources. Unauthenticated access does not require a user to be signed in, and as such, any resources that are made available to unauthenticated users will be public.

15. What do you understand about Cognito Sync?

Cognito Sync is a service that allows applications to synchronize data across devices. This is useful for things like keeping a user’s game progress up-to-date across multiple devices, or making sure that a user’s preferences are consistent across all of their devices.

16. What is the purpose of an Identity Pool in AWS Cognito?

An Identity Pool is used to give your users access to other AWS services. It does this by providing temporary AWS credentials that can be used to access those services.

17. How does AWS Cognito differ from other similar services like Auth0 or Stormpath?

AWS Cognito is a bit more limited in terms of the features it offers compared to something like Auth0 or Stormpath. However, it is also a lot cheaper and is therefore a good option for those on a budget. Additionally, AWS Cognito integrates well with other Amazon services, which can be a big plus for those who are already using Amazon for their web hosting or other needs.

18. What happens if a user tries to log in from two different devices at the same time in AWS Cognito?

If a user tries to log in from two different devices at the same time, AWS Cognito will block the second login attempt and prompt the user to confirm their identity. Once the user has confirmed their identity, they will be able to log in from the second device.

19. What is the maximum number of login attempts allowed per second by the default configuration?

The maximum number of login attempts allowed per second by the default configuration is three.

20. Which version of Python is supported by Cognito?

Cognito supports Python 2.7 and 3.4.