AWS Interview Questions & Answers

1. What is AWS?

   • Answer: Amazon Web Services (AWS) is a cloud computing platform provided by Amazon. It offers a variety of services, including computing power, storage, databases, machine learning, analytics, and more.

2. What is S3?

   • Answer: Amazon Simple Storage Service (S3) is object storage that offers industry-leading scalability, data availability, security, and performance.

3. What is EC2?

   • Answer: Amazon Elastic Compute Cloud (EC2) is a web service that provides resizable compute capacity in the cloud. It is designed to make web-scale cloud computing easier for developers.

4. Explain what an AMI is.

   • Answer: An Amazon Machine Image (AMI) is a pre-configured virtual machine image, which is used to create EC2 instances. It includes the information required to launch an instance, such as the OS, application server, and applications.

5. What is the difference between scalability and elasticity?

   • Answer: Scalability refers to the ability of a system to handle an increasing amount of load or work by adding resources. Elasticity, on the other hand, implies the ability to automatically or dynamically allocate and deallocate resources based on demand.

6. Explain the concept of Regions and Availability Zones.

   • Answer: AWS infrastructure is divided into Regions, each consisting of multiple geographically isolated locations called Availability Zones. Each Region is designed to be completely independent, with its own power, cooling, and networking.

7. What is the VPC (Virtual Private Cloud)?

   • Answer: Amazon Virtual Private Cloud (VPC) allows you to launch Amazon Web Services resources into a virtual network that you've defined.

8. What is an Elastic IP address?

   • Answer: An Elastic IP address is a static IPv4 address designed for dynamic cloud computing. It allows you to associate a persistent IP address with an instance, making it easy to replace instances without affecting the application.

9. Explain the difference between EBS and Instance Store.

   • Answer: Amazon EBS (Elastic Block Store) provides persistent block-level storage volumes for use with Amazon EC2 instances. Instance Store provides temporary block-level storage for instances and is lost when the instance is stopped or terminated.

10. What is AWS Lambda?

    • Answer: AWS Lambda is a serverless computing service that lets you run your code without provisioning or managing servers. You can upload your code, and Lambda automatically takes care of the compute fleet.

11. What is an Auto Scaling Group?

    • Answer: An Auto Scaling Group (ASG) is a group of EC2 instances that automatically adjusts its size based on policies you define. It helps maintain application availability and allows you to scale your Amazon EC2 capacity up or down automatically.

12. What is DynamoDB?

    • Answer: Amazon DynamoDB is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability.

13. Explain the AWS Shared Responsibility Model.

    • Answer: The Shared Responsibility Model defines the security responsibilities between AWS and the customer. AWS is responsible for the security of the cloud infrastructure, while the customer is responsible for securing their data in the cloud.

14. What is CloudFormation?

    • Answer: AWS CloudFormation is a service that allows you to define and provision AWS infrastructure as code in a safe and predictable manner.

15. What is the AWS Well-Architected Framework?

    • Answer: The AWS Well-Architected Framework is a set of best practices to help customers design and build secure, high-performing, resilient, and efficient infrastructure for their applications.

16. Explain Cross-Origin Resource Sharing (CORS).

    • Answer: CORS is a security feature implemented by web browsers that allows or restricts web applications running at one origin to make requests for resources from a different origin.

17. What is Amazon RDS?

    • Answer: Amazon Relational Database Service (RDS) is a managed relational database service that makes it easier to set up, operate, and scale a relational database.

18. What is CloudWatch?

    • Answer: Amazon CloudWatch is a monitoring service for AWS resources and the applications you run on the cloud. It collects and tracks metrics, monitors log files, and sets alarms.

19. Explain the concept of Identity and Access Management (IAM).

    • Answer: IAM is a web service that helps you securely control access to AWS resources. It enables you to create and manage users, groups, and permissions to allow and deny access to AWS resources.

20. What is the AWS Key Management Service (KMS)?

    • Answer: AWS Key Management Service (KMS) is a managed service that makes it easy for you to create and control customer master keys used to encrypt your data.

21. What is the difference between Horizontal Scaling and Vertical Scaling?

    • Answer: Horizontal scaling involves adding more machines to your network, while vertical scaling involves adding more power (CPU, RAM) to an existing machine.

22. What is the AWS Free Tier?

    • Answer: The AWS Free Tier is a program that offers limited access to a variety of AWS services for free. It is designed to help users get started with AWS at no cost.

23. What is CloudTrail?

    • Answer: AWS CloudTrail is a service that enables governance, compliance, operational auditing, and risk auditing of your AWS account.

24. What is Amazon SQS?

    • Answer: Amazon Simple Queue Service (SQS) is a fully managed message queuing service that enables decoupling of the components of a cloud application.

25. Explain the use of AWS Elastic Beanstalk.

    • Answer: AWS Elastic Beanstalk is a fully managed service that makes it easy to deploy and run applications in multiple languages.

26. What is the AWS Marketplace?

    • Answer: The AWS Marketplace is an online store that helps customers find, buy, and immediately start using software and services that run on the AWS Cloud.

27. What is the significance of Amazon Glacier?

    • Answer: Amazon Glacier is a low-cost, long-term cloud storage service designed for archiving and backup.

28. What is Route 53?

    • Answer: Amazon Route 53 is a scalable domain name system (DNS) web service designed to route end-user requests to globally distributed AWS endpoints.

29. Explain the concept of Elastic Load Balancing.

    • Answer: Elastic Load Balancing (ELB) automatically distributes incoming application traffic across multiple targets, such as EC2 instances, in multiple Availability Zones.

30. What is Amazon CloudFront?

    • Answer: Amazon CloudFront is a content delivery network (CDN) service that securely delivers data, videos, applications, and APIs to customers globally.

31. What is the AWS CLI?

    • Answer: The AWS Command Line Interface (CLI) is a unified tool to manage

AWS services directly from the command line.

32. How do you secure data at rest in Amazon S3?

    • Answer: Data at rest in Amazon S3 can be secured using server-side encryption (SSE) with Amazon S3 managed keys (SSE-S3), AWS Key Management Service (SSE-KMS), or server-side encryption with customer-provided keys (SSE-C).

33. What is AWS CloudFormation Stack?

    • Answer: An AWS CloudFormation stack is a collection of AWS resources created and managed as a single unit when using AWS CloudFormation.

34. What is the purpose of AWS Direct Connect?

    • Answer: AWS Direct Connect enables you to establish a dedicated network connection from your on-premises data center to AWS.

35. What is AWS OpsWorks?

    • Answer: AWS OpsWorks is a configuration management service that uses Chef or Puppet to automate how servers are configured, deployed, and managed across your Amazon EC2 instances or on-premises compute environments.

36. Explain the concept of AWS Snowball.

    • Answer: AWS Snowball is a service that helps you transfer large amounts of data into and out of the AWS Cloud using physical storage appliances, bypassing the internet.

37. What is AWS Elastic Load Balancer (ELB)?

    • Answer: AWS Elastic Load Balancer (ELB) is a service that automatically distributes incoming application traffic across multiple Amazon EC2 instances.

38. What is Amazon Aurora?

    • Answer: Amazon Aurora is a fully managed, MySQL and PostgreSQL-compatible relational database engine that combines the performance and availability of high-end commercial databases with the simplicity and cost-effectiveness of open-source databases.

39. Explain the concept of AWS Snowmobile.

    • Answer: AWS Snowmobile is a petabyte-scale data transport solution that uses a secure, ruggedized shipping container to transfer large amounts of data to and from the AWS Cloud.

40. What is Amazon Kinesis?

    • Answer: Amazon Kinesis is a platform for streaming data on AWS, offering capabilities to ingest, buffer, and process data in real-time.

41. How do you secure data in transit in AWS?

    • Answer: Data in transit in AWS can be secured using SSL/TLS protocols for communication. Services like Elastic Load Balancing and Amazon CloudFront provide options for enabling SSL/TLS.

42. What is AWS Elastic Beanstalk environment?

    • Answer: An AWS Elastic Beanstalk environment is an AWS resource collection that lets you run an application.

43. Explain the concept of Amazon EKS.

    • Answer: Amazon Elastic Kubernetes Service (EKS) is a fully managed Kubernetes service that makes it easy to deploy, manage, and scale containerized applications using Kubernetes.

44. What is AWS Cloud9?

    • Answer: AWS Cloud9 is a cloud-based integrated development environment (IDE) that lets you write, run, and debug your code with just a browser.

45. What is AWS WAF?

    • Answer: AWS Web Application Firewall (WAF) is a web application firewall that helps protect web applications from common web exploits.

46. What is AWS Step Functions?

    • Answer: AWS Step Functions is a serverless function orchestration service that allows you to build and run workflows that integrate AWS services.

47. What is the AWS Storage Gateway?

    • Answer: AWS Storage Gateway is a hybrid cloud storage service that enables your on-premises applications to seamlessly use AWS cloud storage.

48. Explain the use of Amazon Neptune.

    • Answer: Amazon Neptune is a fully managed graph database service that makes it easy to build and run applications that work with highly connected datasets.

49. What is Amazon SNS?

    • Answer: Amazon Simple Notification Service (SNS) is a fully managed messaging service that allows you to decouple distributed systems, microservices, and serverless applications.

50. What is AWS CodePipeline?

    • Answer: AWS CodePipeline is a continuous integration and continuous delivery (CI/CD) service that automates the build, test, and deployment phases of your release process.