2024 Best 51 AWS s3 interview questions and answers

Are you sure you are prepared for all the questions on AWS S3 for your next interview? If not, these AWS S3 interview questions and answers may help you get the job!

If you are preparing for AWS interview questions on S3, you need to make sure all the basics are covered. That way, you won’t come off as an amateur even if you are new to the cloud industry.

AWS S3 is among the most popular services for developers that can help you advance your cloud career. Once you are prepared to ace all the AWS interviews you’ve set up for a cloud job, you can look forward to a challenging and fruitful career.

The following AWS interview questions on S3 range from basic to advanced, including scenario-based questions:

AWS s3 interview questions and answers

1. What is AWS S3?

AWS S3 is a Simple Storage Service that we can use for scalability on a large scale. With Amazon’s S3, we can access, store, or recover data from any location on the web. It does not limit the storing of data or the objects’ size–we can store up to 5TBs of data without any issue.

S3 is not only scalable but also high-speed with a low cost compared to web-based services. It’s designed for online backup and enables us to perform the AWS management console tasks.

2. What is an S3 Bucket?

To store data as objects, S3 used buckets. There can be multiple buckets, with each having multiple objects. An object can be a file of any kind, including photo, text, video, etc. It can also have metadata optionally.

We can allow access control for the bucket and determine who can view, create or delete objects within a bucket. We can also view the access logs for the buckets and objects.

See also  2024 Best 51 AWS DevOps Interview Questions

3. How to Manage Access to an S3 Bucket?

Following are some of the common ways for managing access to an S3 bucket:

  • S3 Access Points: Each application has its specific S3 access points that we can use to manage access for S3 datasets.
  • S3 Bucket Policies: We can configure access policies to manage S3 resources’ access. We can also configure permissions at the bucket level that only apply to objects within a bucket.
  • ACL: We can use Access Control List (ACL) to manage access for S3 resources and objects within a bucket.
  • IAM: We can use AWS Identity and Access Management (IAM) Groups, Roles, and Users to manage access to S3 resources.

4. What are the Storage Classes in AWS S3?

Following are some of the storage classes available for S3:

  • S3 Standard Storage Class: If there are no storage classes specified during the upload, the S3 standard class acts as a default storage class.
  • S3 Standard Storage Class for Infrequent Access: When we need to access some data less frequently but rapidly without any delay, we can use the standard storage class for infrequent access.
  • S3 Reduced Redundancy Storage Class: This storage class works better at replicating data in case of lower levels of redundancy. It’s an ideal alternate for S3 standard storage for this specific purpose.
  • S3 Glacier Storage Class: The S3 glacier storage is ideal for low-cost archiving and backup of data. They are equally resilient as the S3 standard storage class.

5. What is AWS S3 Replication?

When we need to copy objects asynchronously, we use S3 replication across the AWS S3 buckets. It is an elastic and fully managed feature with low cost and flexibility in cloud storage.

For all the needs we have related to data sovereignty and business needs, S3 replication can give us the controls for that.

6. What is the Elastic Block Store?

Elastic Block Store (EBS) is a block-level storage solution for Amazon Web Services (AWS).

It can be used with AWS EC2 for storing persistent data, meaning that the data can be stored on EBS regardless of the status of EC2 instances. It provides highly available storage volumes for EC2 instances.

7. What are the Differences between S3 and EBS?

The following table explains the differences between Amazon S3 and EBS:

An object store for Amazon servicesA File system for EC2 Instances
Uses public or private key for securityNone. Can only be used with EC2
Redundancy across data centersRedundancy is only within a data center

8. What is S3 Intelligent Tier?

This is a type of S3 storage class that helps customers save costs by moving objects as per the access level between S3 frequent access and IA.

9. How Would a User Gain Access to a Particular S3 Bucket?

We can follow these steps to provide access to a specific bucket for any user:

  • Step 1: We must categorize the instances
  • Step 2: Determine how authorized users can manage servers
  • Step 3: Locking down the tags
  • Step 4: Attaching the policies for IAM users

10. Explain Versioning in AWS S3

  • It’s a global feature enabled for S3 buckets. Versioning can provide us with a tracking mechanism to keep tabs on the various file changes that occur over time.
  • If we have enabled versioning for S3 buckets, there will be a unique Version ID each time a file is uploaded.
  • Even if two files are the same, if one is uploaded after some modification, both files will get a unique ID and timestamp.
  • Versioning makes it easier to revisit an older file if needed. However, different scenarios can make versioning expensive.
See also  2024 Best AWS Athena Interview Questions And Answers

11. What is an Object Lock Feature in AWS S3?

The object lock feature in AWS S3 enables a user to store their data in write-once-read-many (WORM) format.

This way, the user can prevent the data from being deleted or overwritten for some time or indefinitely. AWS S3 object lock feature is enabled by organizations to meet the WORM storage regulatory requirements.

12. What are the Object Lock Retention Methods?

Following are the two main object retention options:

  • Retention Period: Using this method, a user can define their retention period (days, months, or years) for their object in the S3 bucket. During this time, no one can overwrite or delete the protected object.
  • Legal Holds: In this method, there is no specific duration defined for an object lock. It stays enabled unless a user disables it manually.

13. How Would You Delete an AWS S3 Bucket?

We can follow these steps to delete an AWS S3 bucket:

  • Step 1: Log in to the AWS Management Console and select S3
  • Step 2: Select the bucket that needs to be removed
  • Step 3: Click ‘Delete’ button
  • Step 4: When it prompts you to categorize the bucket name for deletion, write the name
  • Step 5: Click the ‘Confirmation’ button

14. What is the Lifecycle Policy in AWS S3?

The lifecycle policy in S3 determines the data retention rule for objects in an S3 bucket. It’s a policy offered by AWS for storage cost optimization.

With the lifecycle policy, a user can safely define the rules for their data and handle it in a way that data can securely transition via multiple object classes. Once the data is no longer needed, it gets deleted.

There is a limit of 1000 policies per bucket. We can define the lifecycle policy at the level of the bucket; therefore, multiple policies can be applied to a collection of objects.

15. How is the Pricing Policy Determined for AWS S3?

The pricing policy is determined based on the following factors:

  • Utilization of storage
  • Storage management
  • Transfer of data
  • Transfer acceleration
  • Number of requests

16. How Would You Upgrade or Downgrade a System with Near-Zero Downtime?

The following steps can help us upgrade or downgrade a system having near-zero downtime:

  • Step 1: Enter the EC2 console
  • Step 2: Navigate to the AMI operating system
  • Step 3: Use the recent instance type to open an instance
  • Step 4: Install updates and applications
  • Step 5: Check the instance if it’s working or not
  • Step 6: If the instance is working, cover up the old instance with the new one by expanding it
  • Step 7: After the instance is extended, we can upgrade or downgrade a system with near-zero downtime.

17. What is the capacity of s3 bucket?

The S3 buck does provide unlimited capacity in terms of space. You can upload objects ranging from 0 Kb to 5 TB in a bucket. Single upload cannot be more than 5 GB, so make sure to enable Multipart upload.

18. What is CORS in S3?

Cross-Origin Resource Sharing (CORS) is the option that allows one web app to fetch objects from a different domain. It can be enabled from Console, SDK or even using the REST API.

See also  2024 latest 51 AWS Interview Questions for Freshers

19. What is Replication in s3?

This is a feature n S3 where an object placed in one bucket is automatically replicated to a different bucket. This also works with buckets in a separate account.

20. How to view all the objects of a buckets in S3?

In the console, you can view all the files of a bucket but if you are using AWS CLI, you can run the command aws s3 ls –recursive which will give the list of all objects in a bucket.

21. How to protect data at rest in s3?

S3 gives the option of encrypting your data at rest making it safe even at rest.

22. What are the data encryption supported by s3?

S3 supports the below encryption types:

  1. Server Side : S3 encrypts the data here using AWS S3, SSE KMS.
  2. Client Side : Encrypt your data then upload to S3.

23. What is the default bucket policy?

S3 buckets and objects are private by default, you have to explicitly make it public if you would like to make it public. In a new bucket, the owner who created it has access only.

24. Does S3 supports versioning?

Yes, AWS S3 supports versioning only if enabled, it’s not a default option. By enabling versioning you could save different versions of the same file in the same bucket.

25. How to create a bucket using AWS CLI?

The following command creates a bucket from CLI:

aws s3api create-bucket –bucket stepstocloud-bucket –region us-east-2

This command will create the bucket stepstocloud-bucket in the us-east-2 region.


AWS s3 scenario based interview questions

1. Can you host a website in s3?

Yes, we can host a static website from an S3 bucket. So, what is a static website? It is an HTML file with content that does not change, and S3 stores this file and renders the website as a web server. For more detailed steps on how to do it click here.

AWS eC2 and s3 interview questions

1. What are the Differences between S3 and EC2?

The following table contains the differences between S3 and EC2:

Simple Storage Service for scalable storageElastic Compute Cloud to rent virtual computers
Can run both Linux and WindowsFor hosting requests only
Controls applications like Python, PHP, Apache, etc.Data storage system that can store a large number of data

2. How to Recover an EC2 Instance If We Have Lost the Key?

The following steps can recover any EC2 instance if the key is lost:

  • Step 1: Verify EC2Config service is working
  • Step 2: Detach the root volume
  • Step 3: Attach it to a temporary instance
  • Step 4: Alter the configuration file
  • Step 5: Restart your original EC2 instance

You may also like to explore below interview questions on AWS.


The above questions will prepare you for AWS S3 interview questions and answers. The understanding of S3 is important if you want to prosper in the AWS cloud services industry.

We have covered most of the basic questions asked by companies that will get you through an interview about AWS S3. We hope this guide helps you get the job of your dreams.

Check out more on AWS S3 interview questions github.

Leave a Comment