Top 100 Amazon AWS Interview Questions and Answers

Here’s a list of commonly asked Amazon AWS interview questions along with their answers. I’ve broken them down into categories for clarity:

Basic AWS Concepts

1. What is AWS?

   • Answer: AWS (Amazon Web Services) is a comprehensive cloud computing platform provided by Amazon. It offers a variety of services including computing power, storage, and databases, among others, over the internet.

2. What are the key benefits of AWS?

   • Answer: Key benefits include scalability, flexibility, cost-effectiveness, reliability, and a broad set of services.

3. What are the main AWS services for compute?

   • Answer: The primary AWS compute services include Amazon EC2 (Elastic Compute Cloud), AWS Lambda, and Amazon ECS (Elastic Container Service).

4. Explain the difference between Amazon EC2 and AWS Lambda.

   • Answer: Amazon EC2 provides virtual servers to run applications, requiring you to manage the server. AWS Lambda is a serverless compute service that runs code in response to events without managing servers.

5. What is S3 and what are its key features?

   • Answer: Amazon S3 (Simple Storage Service) is an object storage service with high availability and durability. Key features include scalable storage, data encryption, and integration with other AWS services.

6. What is an IAM role?

   • Answer: IAM (Identity and Access Management) roles are used to grant permissions to entities (like users or services) to perform specific actions within AWS. Roles are temporary and can be assumed by users or services.

7. What are the different types of storage offered by AWS?

   • Answer: AWS offers various storage options including Amazon S3 (object storage), Amazon EBS (Elastic Block Store), Amazon EFS (Elastic File System), and AWS Glacier (archival storage).

Networking and Content Delivery

8. What is Amazon VPC?

   • Answer: Amazon VPC (Virtual Private Cloud) allows you to create a logically isolated network within the AWS cloud. It provides control over your network configuration, including IP address ranges, subnets, route tables, and network gateways.

9. Explain the concept of an Elastic Load Balancer (ELB).

   • Answer: ELB distributes incoming application or network traffic across multiple targets, such as EC2 instances, to ensure higher availability and reliability.

10. What is AWS CloudFront?

    • Answer: AWS CloudFront is a content delivery network (CDN) that distributes content globally to users with low latency and high transfer speeds.

11. What is Route 53?

    • Answer: Amazon Route 53 is a scalable DNS web service designed to route end-user requests to endpoints in a globally distributed, low-latency manner.

Databases

12. What is Amazon RDS?

    • Answer: Amazon RDS (Relational Database Service) is a managed relational database service that supports multiple database engines like MySQL, PostgreSQL, Oracle, and SQL Server.

13. What is Amazon DynamoDB?

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

14. How does Amazon Redshift differ from Amazon RDS?

    • Answer: Amazon Redshift is a data warehousing service designed for analyzing large datasets, while Amazon RDS is a relational database service for transactional database needs.

15. What is Amazon Aurora?

    • Answer: Amazon Aurora is a MySQL and PostgreSQL-compatible relational database engine that offers high performance, scalability, and availability.

Security and Identity

16. What is AWS KMS?

    • Answer: AWS KMS (Key Management Service) is a managed service that makes it easy to create and control the encryption keys used to encrypt data.

17. How does AWS IAM differ from AWS Cognito?

    • Answer: AWS IAM (Identity and Access Management) is used for managing access to AWS resources for users and services, while AWS Cognito is used for user sign-up, sign-in, and access control for web and mobile apps.

18. What is AWS Shield?

    • Answer: AWS Shield is a managed DDoS (Distributed Denial of Service) protection service that safeguards applications running on AWS.

19. What are Security Groups in AWS?

    • Answer: Security Groups act as virtual firewalls for EC2 instances, controlling inbound and outbound traffic based on specified rules.

20. What is AWS WAF?

    • Answer: AWS WAF (Web Application Firewall) helps protect web applications from common web exploits and vulnerabilities by defining rules to block or allow web requests.

Monitoring and Management

21. What is Amazon CloudWatch?

    • Answer: Amazon CloudWatch is a monitoring and management service that provides data and actionable insights to monitor AWS resources, applications, and services.

22. What is AWS CloudTrail?

    • Answer: AWS CloudTrail is a service that enables governance, compliance, and operational auditing by recording AWS API calls made on your account.

23. What is AWS Config?

    • Answer: AWS Config is a service that provides AWS resource inventory, configuration history, and configuration change notifications to help you assess compliance and security.

24. What is AWS Systems Manager?

    • Answer: AWS Systems Manager is a management service that enables you to automate operational tasks across AWS resources, such as patch management, configuration management, and instance management.

Deployment and DevOps

25. What is AWS CloudFormation?

    • Answer: AWS CloudFormation is a service that allows you to model and provision AWS resources using templates written in JSON or YAML.

26. What is AWS Elastic Beanstalk?

    • Answer: AWS Elastic Beanstalk is a platform-as-a-service (PaaS) that allows you to deploy and manage applications in various languages without worrying about the underlying infrastructure.

27. What is AWS CodeDeploy?

    • Answer: AWS CodeDeploy is a deployment service that automates code deployments to Amazon EC2 instances, Lambda functions, or on-premises servers.

28. What is AWS CodePipeline?

    • Answer: AWS CodePipeline is a continuous integration and continuous delivery (CI/CD) service for fast and reliable application updates.

29. What is the purpose of AWS CodeBuild?

    • Answer: AWS CodeBuild is a fully managed build service that compiles source code, runs tests, and produces software packages that are ready for deployment.

Advanced Topics

30. What is the AWS Well-Architected Framework?

    • Answer: The AWS Well-Architected Framework provides a set of best practices and guidelines to help you design, build, and maintain secure, high-performing, resilient, and efficient infrastructure for your applications.

31. What is AWS Outposts?

    • Answer: AWS Outposts extends AWS infrastructure, services, APIs, and tools to virtually any on-premises facility for a consistent hybrid cloud experience.

32. What is AWS Snowflake?

    • Answer: AWS Snowflake is a data warehousing service that provides a scalable and high-performance platform for analyzing large volumes of data.

33. What is AWS Fargate?

    • Answer: AWS Fargate is a serverless compute engine for containers that works with Amazon ECS and EKS, allowing you to run containers without managing servers.

34. What is Amazon EKS?

    • Answer: Amazon EKS (Elastic Kubernetes Service) is a managed service that simplifies running Kubernetes on AWS without needing to install and operate your own Kubernetes control plane.

Troubleshooting and Optimization

35. How do you troubleshoot an AWS EC2 instance that is not reachable?

    • Answer: Check the security group rules, network ACLs, and route tables. Verify that the instance is running and has a public IP address or is within the VPC subnet with proper routing.

36. What are some ways to optimize AWS costs?

    • Answer: Use Reserved Instances or Savings Plans, monitor and right-size instances, use spot instances for non-critical workloads, and review and manage unused resources.

37. How do you handle AWS instance scaling?

    • Answer: Use Auto Scaling groups to automatically adjust the number of EC2 instances based on demand. Configure scaling policies and alarms in CloudWatch.

38. What is AWS Trusted Advisor?

    • Answer: AWS Trusted Advisor is an online resource that provides real-time guidance to help you provision your resources following AWS best practices.

39. How can you improve the performance of an Amazon RDS database?

    
    • Answer: Use performance insights and enhanced monitoring, optimize queries, scale the instance size, use read replicas, and adjust database parameters.

40. What steps would you take if you encounter high latency in an application hosted on AWS?

    • Answer: Investigate application code, review CloudWatch metrics for instance performance, optimize database queries, check network configurations, and consider using caching solutions like Amazon ElastiCache.

This list covers a broad range of AWS topics. For an in-depth preparation, you might want to explore each topic further based on the specific role you are applying for.

Here are additional AWS interview questions across various domains:

Advanced Networking

41. What is a NAT Gateway and why is it used?

    • Answer: A NAT Gateway allows instances in a private subnet to connect to the internet or other AWS services while preventing inbound traffic from the internet. It’s used for scenarios where you need instances in private subnets to access the internet for updates or downloads.

42. How does AWS Direct Connect work?

    • Answer: AWS Direct Connect provides a dedicated network connection from your on-premises data center to AWS, offering higher bandwidth, lower latency, and more consistent network performance compared to internet-based connections.

43. What is VPC Peering?

    • Answer: VPC Peering is a networking connection between two VPCs that enables them to communicate with each other as if they were within the same network. This is useful for sharing resources across VPCs.

44. Explain AWS Transit Gateway.

    • Answer: AWS Transit Gateway is a network hub that allows you to connect multiple VPCs and on-premises networks through a central gateway, simplifying network management and reducing complexity.

Security

45. What is the difference between AWS IAM policies and AWS ACLs?

    • Answer: IAM policies are used to define permissions for AWS services and resources at a granular level, while ACLs (Access Control Lists) are used for managing permissions at the network level, such as for S3 buckets or VPCs.

46. How does AWS Secrets Manager differ from AWS Parameter Store?

    • Answer: AWS Secrets Manager is designed to manage and rotate secrets like database credentials, while AWS Parameter Store provides a central store for configuration data and secrets, but with less emphasis on automatic rotation.

47. What are AWS Security Hub and AWS Inspector?

    • Answer: AWS Security Hub provides a comprehensive view of your security state across AWS accounts and services. AWS Inspector is a security assessment service that helps identify vulnerabilities or deviations from best practices in your EC2 instances.

48. What is AWS GuardDuty?

    • Answer: AWS GuardDuty is a threat detection service that continuously monitors for malicious or unauthorized behavior to protect your AWS accounts, workloads, and data.

Databases and Data Management

49. What is Amazon Neptune?

    • Answer: Amazon Neptune is a managed graph database service that supports two popular graph models: Property Graph and RDF (Resource Description Framework), enabling you to build and query complex relationships in your data.

50. Explain Amazon ElastiCache.

    • Answer: Amazon ElastiCache is a service that adds caching layers to your applications to improve performance by reducing the load on your databases. It supports Redis and Memcached.

51. How does Amazon Aurora handle high availability?

    • Answer: Amazon Aurora replicates data across multiple Availability Zones and continuously backs up data to Amazon S3. It automatically fails over to a replica in case of an issue with the primary instance.

52. What is AWS DMS?

    • Answer: AWS DMS (Database Migration Service) helps you migrate databases to AWS easily and securely. It supports homogeneous and heterogeneous migrations.

Storage and Content Delivery

53. What are the different storage classes in Amazon S3?

    • Answer: Storage classes include S3 Standard, S3 Intelligent-Tiering, S3 One Zone-IA, S3 Glacier, and S3 Glacier Deep Archive, each offering different levels of durability, availability, and cost.

54. Explain the concept of S3 Object Lifecycle Management.

    • Answer: S3 Object Lifecycle Management automates the transition of objects to different storage classes or deletion based on specified rules, helping manage costs and compliance.

55. What is AWS Snowball?

    • Answer: AWS Snowball is a data transfer service that uses physical devices to transfer large amounts of data into and out of AWS securely and efficiently.

56. What is the AWS Storage Gateway?

    • Answer: AWS Storage Gateway is a hybrid cloud storage service that enables on-premises applications to seamlessly use cloud storage for backup, archiving, and disaster recovery.

Application Integration and Messaging

57. What is Amazon SNS?

    • Answer: Amazon SNS (Simple Notification Service) is a messaging service that allows you to send notifications to subscribers or other applications via email, SMS, or other protocols.

58. What is Amazon SQS?

    • Answer: Amazon SQS (Simple Queue Service) is a fully managed message queuing service that enables decoupling and scaling of microservices, distributed systems, and serverless applications.

59. Explain AWS Step Functions.

    • Answer: AWS Step Functions is a serverless orchestration service that lets you coordinate multiple AWS services into serverless workflows so you can build and update apps quickly.

60. What is Amazon EventBridge?

    • Answer: Amazon EventBridge is a serverless event bus service that allows you to build event-driven applications by connecting different AWS services with your applications using events.

Serverless and Containers

61. What are AWS Lambda Layers?

    • Answer: AWS Lambda Layers are a way to manage and share code and dependencies across multiple Lambda functions, enabling modularity and reducing duplication.

62. How does AWS Lambda handle scaling?

    • Answer: AWS Lambda automatically scales by running code in response to incoming events. Each event is processed by a separate execution environment, and AWS manages scaling automatically.

63. What is AWS App Runner?

    • Answer: AWS App Runner is a fully managed service that makes it easy to build and run containerized web applications and APIs at scale without managing infrastructure.

64. What is Amazon ECS and how does it differ from Amazon EKS?

    • Answer: Amazon ECS (Elastic Container Service) is a managed container orchestration service that supports Docker containers. Amazon EKS (Elastic Kubernetes Service) provides managed Kubernetes clusters.

Monitoring and Optimization

65. How can you monitor AWS resources and applications?

    • Answer: You can use AWS CloudWatch for monitoring metrics and logs, AWS X-Ray for distributed tracing, and AWS CloudTrail for auditing API calls.

66. What is AWS Compute Optimizer?

    • Answer: AWS Compute Optimizer helps you choose the right instance types for your workloads based on analysis of your historical usage and recommendations.

67. Explain the use of AWS Trusted Advisor.

    • Answer: AWS Trusted Advisor provides real-time guidance to help you provision your AWS resources following best practices across cost optimization, security, fault tolerance, performance, and service limits.

68. What is AWS Cost Explorer?

    • Answer: AWS Cost Explorer is a tool that enables you to view and analyze your AWS spending and usage patterns to help manage costs and optimize your budget.

Deployment and Automation

69. What is AWS CodeStar?

    • Answer: AWS CodeStar is a cloud-based service that provides a unified user interface for managing the software development lifecycle, including planning, coding, building, testing, and deploying applications.

70. What is the AWS Elastic Container Registry (ECR)?

    • Answer: AWS ECR is a fully managed Docker container registry that makes it easy to store, manage, and deploy Docker container images.

71. Explain how AWS CloudFormation can be used for infrastructure as code.

    • Answer: AWS CloudFormation allows you to define and provision AWS infrastructure using code in JSON or YAML templates, enabling automated and consistent deployments of resources.

72. What is AWS OpsWorks?

    • Answer: AWS OpsWorks is a configuration management service that provides managed instances of Chef and Puppet, allowing you to automate server configurations and deployment.

Hybrid Cloud and Edge Computing

73. What is AWS Outposts and how does it integrate with the cloud?

    • Answer: AWS Outposts extends AWS infrastructure and services to on-premises locations, providing a consistent hybrid cloud experience with native AWS tools and APIs.

74. What is AWS Snowcone?

    • Answer: AWS Snowcone is a small, portable edge computing and data transfer device that provides local processing and storage for data before transferring it to AWS.

75. Explain AWS Local Zones.

    • Answer: AWS Local Zones are an extension of an AWS Region that places compute, storage, and database services closer to large population centers, providing low-latency access to applications.

76. What is AWS Greengrass?

    • Answer: AWS Greengrass is an IoT service that extends AWS capabilities to edge devices, allowing them to act locally on data while seamlessly integrating with the cloud.

Data Analytics and Machine Learning

77. What is Amazon Athena?

    • Answer: Amazon Athena is an interactive query service that makes it easy to analyze data in Amazon S3 using standard SQL without needing to set up complex infrastructure.

78. What is AWS Glue?

    • Answer: AWS Glue is a fully managed ETL (extract, transform, load) service that automates the process of preparing and loading data for analytics.

79. Explain Amazon SageMaker.

    • Answer: Amazon SageMaker is a fully managed service that provides tools and workflows for building, training, and deploying machine learning models at scale.

80. What is Amazon EMR?

    • Answer: Amazon EMR (Elastic MapReduce) is a cloud big data platform that provides a managed framework for processing and analyzing large amounts of data using open-source tools like Apache Hadoop and Apache Spark.

Compliance and Governance

81. What is AWS Organizations?

    • Answer: AWS Organizations allows you to manage and consolidate billing across multiple AWS accounts, set policies, and control access across accounts.

82. What is AWS Control Tower?

    • Answer: AWS Control Tower is a service that automates the setup of a multi-account AWS environment, implementing best practices and governance for managing and operating your AWS environment.

83. How does AWS Artifact help with compliance?

    • Answer: AWS Artifact provides on-demand access to AWS compliance reports and security and compliance documentation to help you meet regulatory requirements.

84. What is AWS Config Rules?

    • Answer: AWS Config Rules allows you to define and enforce policies for AWS resource configurations to ensure compliance with internal policies and best practices.

Miscellaneous

85. What is AWS Marketplace?

    • Answer: AWS Marketplace is a digital catalog of software, services, and data that you can buy and deploy on AWS, including third-party solutions and pre-configured applications.

86. What are AWS Reserved Instances?

    • Answer: Reserved Instances provide a significant discount (up to 75%) compared to on-demand pricing in exchange for committing to a specific instance type and region for a one or three-year term.

87. What is the difference between On-Demand and Spot Instances?

    • Answer: On-Demand Instances are billed at a fixed rate and are ideal for unpredictable workloads, while Spot Instances offer unused EC2 capacity at a lower cost but can be interrupted with little notice.

88. How do you implement high availability in AWS?

    • Answer: Implement high availability by using multiple Availability Zones, employing load balancers, using Auto Scaling, and implementing fault-tolerant architectures.

89. What is the purpose of AWS Global Accelerator?

    • Answer: AWS Global Accelerator improves the availability and performance of your applications by directing traffic to the optimal AWS endpoint based on health, geography, and routing policies.

90. Explain the concept of AWS Well-Architected Review.

    • Answer: The AWS Well-Architected Review helps evaluate the design of your workloads against AWS best practices, focusing on operational excellence, security, reliability, performance efficiency, and cost optimization.

91. What are AWS Service Quotas?

    • Answer: AWS Service Quotas help manage and monitor the limits on the number of resources and operations you can use within AWS services, and you can request quota increases if needed.

92. How do you use AWS Elastic File System (EFS)?

    • Answer: AWS EFS provides scalable, elastic file storage that can be accessed by multiple EC2 instances concurrently, making it suitable for use cases that require a shared file system.

93. What is Amazon WorkSpaces?

    • Answer: Amazon WorkSpaces is a managed, secure Desktop-as-a-Service (DaaS) solution that allows you to provision virtual desktops for your users.

94. What is AWS Elemental MediaConvert?

    • Answer: AWS Elemental MediaConvert is a file-based video transcoding service that allows you to convert video content into multiple formats for on-demand delivery.

95. What are Amazon CloudWatch Logs Insights?

    • Answer: Amazon CloudWatch Logs Insights is an interactive log analytics service that helps you query, visualize, and analyze log data in CloudWatch Logs.

96. What is AWS Control Tower?

    • Answer: AWS Control Tower provides a managed service to set up and govern a secure, multi-account AWS environment based on AWS best practices.

97. Explain AWS Auto Scaling.

    • Answer: AWS Auto Scaling automatically adjusts the number of EC2 instances or other resources based on demand to ensure that you have the right number of resources available.

98. What is the AWS Resource Access Manager (RAM)?

    • Answer: AWS RAM enables you to share AWS resources across multiple AWS accounts or within an AWS Organization, simplifying resource management.

99. What is Amazon Kinesis?

    • Answer: Amazon Kinesis is a platform for real-time data streaming and analytics, allowing you to collect, process, and analyze large streams of data records in real time.

100. What is AWS Cloud Development Kit (CDK)? - Answer: AWS Cloud Development Kit (CDK) is an open-source software development framework that allows you to define cloud infrastructure using familiar programming languages.

This extended list should help you cover a wide range of topics for AWS interviews. Good luck with your preparation!