AWS Services

1. What is AWS?
2. What are the different types of cloud computing models?
3. Explain EC2 instance types.
4. What is an AWS region and availability zone?
5. What is Elastic Load Balancing (ELB)?
6. What is AWS Lambda and how does it work?
7. How do you secure your EC2 instances?
8. What is S3, and how can you use it in your application?
9. What is Amazon RDS, and what are its benefits?
10. How can you ensure high availability for an application in AWS?
11. What is the difference between S3 and EBS (Elastic Block Store)?
12. What are IAM roles and policies?
13. What is CloudFormation?
14. How would you use AWS with a Java-based backend?
15. What is the difference between EC2 and Lambda?
16. What is Amazon CloudWatch?
17. What is AWS SQS (Simple Queue Service)?
18. What is the AWS VPC (Virtual Private Cloud)?
19. What is Amazon DynamoDB?
20. How would you secure your S3 bucket?
21. What is Amazon SNS (Simple Notification Service)?
22. What is AWS Elastic Beanstalk?
23. Explain the concept of Auto Scaling.
24. What is AWS Direct Connect?
25. What is AWS WAF (Web Application Firewall)?
26. What is AWS CloudTrail?
27. What is the difference between Amazon EC2 and Amazon Lambda?
28. What is AWS Elastic File System (EFS)?
29. Explain the concept of AWS Redshift.
30. What is Amazon Aurora?
31. What is the role of Amazon API Gateway?
32. What is the difference between a public and a private subnet in AWS?
33. How do you manage access to your AWS resources using IAM?
34. What is AWS Batch?
35. What is Amazon Elasticache?
36. Explain how Amazon CloudFront works.
37. What are security groups in AWS?
38. What is the difference between AWS S3 and Glacier?
39. What are AWS Global Accelerator and how is it different from Route 53?
40. What is Amazon Kinesis?
41. How do you secure sensitive data in AWS?
42. What is the purpose of a VPN in AWS?
43. What is the AWS Shared Responsibility Model?
44. What is AWS CodePipeline?
45. What are Lambda layers?
46. What is Amazon Route 53?
47. How does AWS handle scaling?
48. What is AWS Trusted Advisor?
49. What is AWS Snowball?
50. What is AWS Cost Explorer?
51. What is the difference between EBS and Instance Store?
52. What is AWS CloudHSM?
53. How do you ensure data integrity in AWS?
54. What are the benefits of using Amazon S3 over traditional file systems?
55. What is AWS Well-Architected Framework?
56. What is the purpose of Amazon EC2 Auto Scaling?
57. What is AWS CloudFormation Stack?
58. What is Amazon Macie?
59. What are VPC Peering and Transit Gateway?
60. What is the difference between a security group and a network ACL?
61. What is AWS Global Accelerator used for?
62. Explain the concept of Amazon S3 event notifications.
63. What are Amazon CloudWatch Logs?
64. What is AWS Direct Connect and its benefits?
65. How do you implement disaster recovery in AWS?
66. What is the AWS Key Management Service (KMS)?
67. What is Amazon Elastic Container Service (ECS)?
68. What is Amazon Elastic Kubernetes Service (EKS)?
69. What is Amazon S3 Transfer Acceleration?
70. What is AWS Cognito?
71. What is Amazon Lightsail?
72. What is the difference between AWS Lambda and EC2?
73. How does AWS support Hybrid Cloud environments?
74. What is Amazon Aurora Serverless?
75. What is Amazon SQS FIFO queues?
76. What is AWS Batch and how does it work?
77. How would you monitor your AWS resources?
78. What is the difference between S3 and EFS?
79. What is the maximum size of an object you can upload to S3?
80. What is Amazon CloudWatch Alarms?
81. What is Amazon Elastic Beanstalk Environment?
82. What is AWS Elastic Beanstalk, and how does it help developers?
83. How would you use AWS Lambda with Java?
84. How do you handle serverless architectures using AWS Lambda?
85. What is Amazon API Gateway and how does it integrate with AWS Lambda?
86. How do you manage state in a serverless application using AWS Lambda?
87. What are Amazon SQS and its use cases in a Java application?
88. How would you handle message ordering and duplication in Amazon SQS?
89. How do you use Amazon S3 in a Java application?
90. What is the significance of IAM roles for Lambda functions in AWS?
91. How can you implement a microservices architecture in AWS?
92. What is AWS Glue, and how can it be used with Java-based ETL workloads?
93. What is the role of Amazon Elastic File System (EFS) in a Java application?
94. How do you secure Java applications deployed on AWS?
95. How do you manage large amounts of unstructured data in AWS using Java?
96. What is Amazon Kinesis, and how can it be integrated with Java-based applications?
97. How would you implement a backup and recovery strategy for a Java application using AWS services?
98. How do you handle cross-region replication in AWS?
99. What is the AWS SDK for Java and how do you use it in backend applications?
100. How do you monitor the performance of a Java application running on AWS?

1. What is AWS?

AWS (Amazon Web Services) is a cloud platform offered by Amazon that provides a wide range of cloud computing services, such as computing power, storage options, networking, databases, and more.
Answer: AWS offers services such as EC2 (Elastic Compute Cloud), S3 (Simple Storage Service), RDS (Relational Database Service), Lambda, and many others to help organizations run applications on the cloud without having to manage physical servers.

2. What are the different types of cloud computing models?

The three main models of cloud computing are:

• IaaS (Infrastructure as a Service): Provides virtualized computing resources over the internet (e.g., EC2).

• PaaS (Platform as a Service): Provides hardware and software tools over the internet (e.g., Elastic Beanstalk).

• SaaS (Software as a Service): Delivers software applications over the internet (e.g., AWS WorkDocs).

3. Explain EC2 instance types.

EC2 instances are virtual servers in AWS, which come in various types optimized for different workloads.

• General Purpose (T2, M5)

• Compute Optimized (C5)

• Memory Optimized (R5)

• Storage Optimized (I3)

• Accelerated Computing (P3)

4. What is an AWS region and availability zone?

AWS regions are separate geographical areas, and each region contains multiple Availability Zones (AZs), which are isolated locations within a region. AZs are designed to be independent to avoid failures affecting multiple zones at the same time.

5. What is Elastic Load Balancing (ELB)?

ELB is a service that automatically distributes incoming application traffic across multiple targets (such as EC2 instances) to ensure high availability and reliability.

6. What is AWS Lambda and how does it work?

AWS Lambda is a serverless compute service that allows you to run code without provisioning or managing servers. You upload the code, set the trigger (e.g., an S3 event or an HTTP request via API Gateway), and Lambda takes care of the rest.

7. How do you secure your EC2 instances?

EC2 instances can be secured using:

• Security Groups: Firewalls that control inbound and outbound traffic.

• Key Pairs: SSH keys for secure login.

• IAM Roles: To assign specific permissions for services to interact with the instance.

8. What is S3, and how can you use it in your application?

Amazon S3 (Simple Storage Service) is a scalable object storage service that can store files, images, backups, and other data. You can use it in a Java application to store and retrieve files using the AWS SDK for Java.

9. What is Amazon RDS, and what are its benefits?

Amazon RDS (Relational Database Service) is a managed relational database service supporting multiple engines like MySQL, PostgreSQL, Oracle, and SQL Server. It handles backups, patching, and scaling automatically.

10. How can you ensure high availability for an application in AWS?

High availability in AWS can be achieved by:

• Using multiple Availability Zones (AZs) for your EC2 instances, load balancers, and databases.

• Auto Scaling to adjust capacity based on traffic.

• Using Amazon Route 53 for DNS failover.

11. What is the difference between S3 and EBS (Elastic Block Store)?

• S3 is object storage used for storing large amounts of unstructured data (e.g., files, backups).

• EBS is block storage that is used as persistent storage for EC2 instances.

12. What are IAM roles and policies?

IAM (Identity and Access Management) allows you to manage users and permissions in AWS.

• IAM Roles: These are a set of permissions you assign to AWS services to perform actions.

• IAM Policies: These are JSON documents defining permissions (e.g., allowing access to S3 buckets).

13. What is CloudFormation?

AWS CloudFormation is a service that allows you to define your infrastructure as code, enabling automated provisioning of resources like EC2 instances, security groups, and RDS databases.

14. How would you use AWS with a Java-based backend?

For a Java backend, you can integrate AWS services using the AWS SDK for Java. You can interact with services like S3 for file storage, RDS for database management, and Lambda for serverless architecture.

15. What is the difference between EC2 and Lambda?

• EC2 provides fully managed virtual servers, where you have control over the underlying operating system and resources.

• Lambda is serverless, where you only manage code and do not worry about the infrastructure or scaling.

16. What is Amazon CloudWatch?

Amazon CloudWatch is a monitoring service that provides real-time visibility into your AWS resources and applications. It collects and tracks metrics, logs, and events to help you monitor and troubleshoot.

17. What is AWS SQS (Simple Queue Service)?

AWS SQS is a fully managed message queuing service. It allows decoupling of microservices by storing messages until the receiving system is ready to process them.

18. What is the AWS VPC (Virtual Private Cloud)?

AWS VPC is a private network that you can create within AWS. It enables you to launch AWS resources (such as EC2 instances) into a virtual network that you define.

19. What is Amazon DynamoDB?

DynamoDB is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability. It is ideal for applications that need consistent, low-latency data access.

20. How would you secure your S3 bucket?

You can secure S3 buckets by:

• Enabling bucket policies to restrict access.

• Using IAM roles for controlling access.

• Implementing encryption (SSE) for data at rest.

• Versioning to keep track of changes to objects.

21. What is Amazon SNS (Simple Notification Service)?

SNS is a fully managed service that provides message delivery from publishers to subscribers. It supports push notifications, emails, and SMS messages.

22. What is AWS Elastic Beanstalk?

AWS Elastic Beanstalk is a Platform-as-a-Service (PaaS) offering that allows you to deploy and manage Java applications quickly and easily. It supports Java, Node.js, Python, Ruby, and other languages.

23. Explain the concept of Auto Scaling.

Auto Scaling is a feature that automatically adjusts the number of EC2 instances based on demand, ensuring you always have the right amount of compute power.

24. What is AWS Direct Connect?

AWS Direct Connect is a service that establishes a dedicated network connection from your on-premise data center to AWS, bypassing the public internet for better security and lower latency.

25. What is AWS WAF (Web Application Firewall)?

AWS WAF helps protect your applications from common web exploits and vulnerabilities. It allows you to filter web traffic based on IP addresses, HTTP headers, and other attributes.

26. What is AWS CloudTrail?

AWS CloudTrail is a service that enables governance, compliance, and operational and risk auditing of your AWS account. It records API calls made on your account, providing event history for security analysis.

27. What is the difference between Amazon EC2 and Amazon Lambda?

• EC2 provides full control over virtual machines (VMs) where you can install software and manage the infrastructure.

• Lambda is serverless, where you only write functions, and AWS takes care of the infrastructure, scaling, and management.

28. What is AWS Elastic File System (EFS)?

AWS EFS is a fully managed file storage service that can be accessed by multiple EC2 instances concurrently. It provides scalable, high-performance file storage for workloads that require file-based storage.

29. Explain the concept of AWS Redshift.

Amazon Redshift is a fully managed, petabyte-scale data warehouse service in AWS. It allows you to run complex queries and analytics on large datasets, making it ideal for big data processing.

30. What is Amazon Aurora?

Amazon Aurora is a MySQL and PostgreSQL-compatible relational database built for the cloud, providing performance and availability similar to commercial databases at a fraction of the cost.

31. What is the role of Amazon API Gateway?

Amazon API Gateway is a fully managed service that allows you to create, publish, maintain, monitor, and secure APIs for your backend services, including Lambda functions, EC2 instances, and other AWS services.

32. What is the difference between a public and a private subnet in AWS?

• Public Subnet: A subnet that is connected to the internet, usually through an Internet Gateway, and allows inbound and outbound traffic from/to the internet.

• Private Subnet: A subnet that does not have direct access to the internet. It is typically used for backend resources that should not be exposed to the public.

33. How do you manage access to your AWS resources using IAM?

AWS IAM (Identity and Access Management) allows you to create users, groups, and roles to manage permissions. You can attach IAM policies to these entities to specify who can access what resources and actions within AWS.

34. What is AWS Batch?

AWS Batch enables you to run batch computing workloads on the AWS Cloud. It dynamically provisions resources and manages job queues for running large-scale parallel and high-performance computing workloads.

35. What is Amazon Elasticache?

Amazon Elasticache is a fully managed caching service that supports both Redis and Memcached. It is used to improve the performance of web applications by caching frequently accessed data.

36. Explain how Amazon CloudFront works.

Amazon CloudFront is a Content Delivery Network (CDN) that accelerates the delivery of your content (e.g., static files, videos, APIs) by caching copies of your content in multiple edge locations worldwide.

37. What are security groups in AWS?

Security Groups are virtual firewalls in AWS that control the inbound and outbound traffic to your resources (e.g., EC2 instances). They are stateful, meaning if you allow inbound traffic, the return traffic is automatically allowed.

38. What is the difference between AWS S3 and Glacier?

• S3 is designed for frequent access to data.

• Glacier is a low-cost storage service designed for data archiving and long-term backup with retrieval times ranging from minutes to hours.

39. What are AWS Global Accelerator and how is it different from Route 53?

• Global Accelerator is a service that improves the availability and performance of your application by directing user traffic to the nearest edge location.

• Route 53 is a scalable DNS web service used to route traffic to resources such as EC2 instances, S3 buckets, etc.

40. What is Amazon Kinesis?

Amazon Kinesis is a platform for streaming data on AWS. It enables you to collect, process, and analyze real-time, streaming data such as video, application logs, and telemetry data.

41. How do you secure sensitive data in AWS?

You can secure sensitive data in AWS using:

• Encryption: For data at rest (using services like S3, RDS, and EBS) and in transit (using SSL/TLS).

• IAM Policies and Roles: To restrict access to sensitive resources.

• AWS Secrets Manager: For securely storing and managing sensitive information such as API keys, passwords, etc.

42. What is the purpose of a VPN in AWS?

A VPN (Virtual Private Network) in AWS allows you to securely connect your on-premises network to your AWS VPC over an encrypted tunnel, providing private, secure communication between them.

43. What is the AWS Shared Responsibility Model?

The AWS Shared Responsibility Model defines the security responsibilities of both AWS and the customer. AWS is responsible for security of the cloud (infrastructure, physical hardware), and the customer is responsible for security in the cloud (e.g., data, identity management).

44. What is AWS CodePipeline?

AWS CodePipeline is a fully managed continuous delivery service that automates the building, testing, and deployment of applications to AWS environments. It helps implement CI/CD pipelines for faster delivery.

45. What are Lambda layers?

Lambda layers are a distribution mechanism for Lambda functions, allowing you to manage and share common code or libraries across multiple functions. Layers allow code reuse and version control.

46. What is Amazon Route 53?

Route 53 is a scalable DNS web service in AWS that translates friendly domain names to IP addresses. It also offers health checking, domain registration, and routing policies.

47. How does AWS handle scaling?

AWS supports both vertical and horizontal scaling:

• Vertical Scaling: Increasing the resources (e.g., CPU, RAM) of an existing instance.

• Horizontal Scaling: Adding more instances to distribute the load.

48. What is AWS Trusted Advisor?

AWS Trusted Advisor is an online resource to help you reduce cost, increase performance, and improve security. It provides real-time recommendations based on AWS best practices.

49. What is AWS Snowball?

AWS Snowball is a petabyte-scale data transfer service that helps you transfer large amounts of data to and from AWS using physical devices, such as hard drives, to reduce the time and cost of data migration.

50. What is AWS Cost Explorer?

AWS Cost Explorer allows you to visualize and manage AWS costs and usage over time. You can analyze and create reports on how much you're spending on AWS services.

51. What is the difference between EBS and Instance Store?

• EBS (Elastic Block Store) is persistent block-level storage attached to an EC2 instance.

• Instance Store is temporary storage that is tied to the lifecycle of an EC2 instance. Data is lost when the instance is terminated.

52. What is AWS CloudHSM?

AWS CloudHSM is a hardware security module (HSM) service that allows you to generate and use your own encryption keys on the AWS cloud.

53. How do you ensure data integrity in AWS?

Data integrity can be ensured in AWS using:

• Checksums and hash functions for validating data integrity during uploads (e.g., S3 supports MD5 checksums).

• AWS Backup for scheduled and automated backups.

• Versioning in S3 to keep track of data changes.

54. What are the benefits of using Amazon S3 over traditional file systems?

• Scalability: No need to provision storage.

• Durability: 99.999999999% durability over a year.

• Accessibility: Access from anywhere via APIs.

• Cost: Pay only for the storage you use.

55. What is AWS Well-Architected Framework?

The AWS Well-Architected Framework is a set of best practices designed to help you build secure, high-performing, resilient, and efficient infrastructure for your applications in the cloud.

56. What is the purpose of Amazon EC2 Auto Scaling?

Amazon EC2 Auto Scaling automatically adjusts the number of EC2 instances in response to changing traffic patterns, ensuring that your application can handle traffic spikes without over-provisioning resources.

57. What is AWS CloudFormation Stack?

A CloudFormation stack is a collection of AWS resources that you create and manage as a single unit. You define the resources in a CloudFormation template, and AWS provisions and manages them for you.

58. What is Amazon Macie?

Amazon Macie is a security service that uses machine learning to automatically discover, classify, and protect sensitive data in AWS, helping organizations comply with data privacy regulations.

59. What are VPC Peering and Transit Gateway?

• VPC Peering allows you to connect two VPCs to route traffic between them.

• AWS Transit Gateway acts as a hub that interconnects multiple VPCs and on-premises networks.

60. What is the difference between a security group and a network ACL?

• Security Groups: Statefull, operates at the instance level, controls inbound and outbound traffic.

• Network ACLs: Stateless, operates at the subnet level, controls both inbound and outbound traffic.

61. What is AWS Global Accelerator used for?

AWS Global Accelerator improves the performance of your applications by directing user traffic to the nearest available endpoint, whether that is in the same region or another region, based on the optimal routing path.

62. Explain the concept of Amazon S3 event notifications.

S3 event notifications are used to send notifications for specific events like object creation, deletion, or update. These notifications can trigger AWS Lambda functions, SQS queues, or SNS topics.

63. What are Amazon CloudWatch Logs?

Amazon CloudWatch Logs helps you monitor, store, and access log files from various AWS resources like EC2 instances, Lambda functions, and CloudTrail logs. You can use CloudWatch Logs to track metrics, troubleshoot applications, and monitor operational health.

64. What is AWS Direct Connect and its benefits?

AWS Direct Connect establishes a dedicated network connection between your on-premises data center and AWS, providing better security, lower latency, and higher bandwidth than standard internet connections.

65. How do you implement disaster recovery in AWS?

You can implement disaster recovery in AWS by using:

• Multi-Region Deployments: Replicating resources in multiple regions.

• Snapshots and Backups: Regular snapshots and backups of EC2 instances, RDS databases, and other data.

• Route 53 Failover: Using Route 53 health checks and failover routing to redirect traffic to a backup region if primary resources fail.

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

AWS KMS is a managed service that enables you to create and control encryption keys used to encrypt data. It integrates with other AWS services to provide encryption at rest and in transit.

67. What is Amazon Elastic Container Service (ECS)?

Amazon ECS is a fully managed container orchestration service that allows you to run Docker containers on a scalable cluster of EC2 instances. It can be used to deploy and manage microservices applications in production.

68. What is Amazon Elastic Kubernetes Service (EKS)?

Amazon EKS is a fully managed Kubernetes service that makes it easy to run Kubernetes on AWS without the need to install or manage your own Kubernetes control plane.

69. What is Amazon S3 Transfer Acceleration?

S3 Transfer Acceleration speeds up the transfer of files to and from Amazon S3 by using Amazon CloudFront’s globally distributed edge locations, reducing latency.

70. What is AWS Cognito?

AWS Cognito is a service that provides authentication, authorization, and user management for your web and mobile applications. It supports social login (e.g., Facebook, Google) and enterprise login (e.g., SAML).

71. What is Amazon Lightsail?

Amazon Lightsail is an easy-to-use cloud platform that provides compute, storage, and networking resources for developers to quickly launch and manage simple applications, often with pre-configured development stacks.

72. What is the difference between AWS Lambda and EC2?

• Lambda is serverless, event-driven, and runs your code without provisioning or managing servers.

• EC2 provides full control over virtual machines, including operating systems and software, and requires manual scaling and provisioning.

73. How does AWS support Hybrid Cloud environments?

AWS supports hybrid cloud environments through services like:

• AWS Direct Connect for private network connections.

• AWS Storage Gateway for integrating on-premises storage with cloud storage.

• AWS Outposts for running AWS infrastructure on-premises.

74. What is Amazon Aurora Serverless?

Amazon Aurora Serverless is an on-demand, auto-scaling version of Amazon Aurora that automatically adjusts the database capacity based on application needs, helping reduce costs while providing high availability.

75. What is the AWS Free Tier?

The AWS Free Tier offers a limited set of AWS services for free, intended for new customers to explore and try out AWS services. It includes free usage for services like EC2, S3, and Lambda, with certain usage limits.

76. What is AWS Marketplace?

AWS Marketplace is an online store where customers can find, test, and buy software that runs on AWS, including applications, development tools, and operating systems.

77. What is Amazon Redshift Spectrum?

Amazon Redshift Spectrum is an extension of Amazon Redshift that allows you to query data directly from Amazon S3 without having to load it into Redshift tables, enabling you to run analytics on vast amounts of data.

78. What is Amazon RDS Multi-AZ Deployment?

Amazon RDS Multi-AZ deployment provides high availability and failover support for DB instances. It automatically replicates your data to a standby instance in another Availability Zone to ensure availability during failures.

79. What is AWS Shield?

AWS Shield is a managed Distributed Denial of Service (DDoS) protection service that protects AWS applications from malicious attacks. AWS Shield offers two levels: Standard (free) and Advanced (premium).

80. What are AWS Lambda triggers?

AWS Lambda triggers are events that invoke Lambda functions. Triggers include S3 object uploads, DynamoDB streams, API Gateway requests, and CloudWatch Events, among others.

81. What is Amazon WorkSpaces?

Amazon WorkSpaces is a managed Desktop-as-a-Service (DaaS) solution that allows you to provide cloud-based virtual desktops to end-users, which can be accessed from any device.

82. What is AWS Glue?

AWS Glue is a fully managed ETL (Extract, Transform, Load) service that makes it easy to move data between data stores. It automates the process of discovering, cataloging, transforming, and loading data into data lakes or data warehouses.

83. What is Amazon QuickSight?

Amazon QuickSight is a scalable, serverless business intelligence (BI) service that allows you to create and publish interactive dashboards and reports based on data stored in AWS services like S3, Redshift, and RDS.

84. What is AWS DataSync?

AWS DataSync is a service that automates the transfer of large amounts of data between on-premises storage and AWS, or between AWS services like S3, EFS, and FSx.

85. What is Amazon FSx?

Amazon FSx provides fully managed Windows and Lustre file systems. FSx for Windows File Server provides shared storage for Windows applications, while FSx for Lustre is designed for high-performance computing workloads.

86. What is AWS X-Ray?

AWS X-Ray helps developers analyze and debug production applications, particularly in microservices architectures. It provides insights into performance bottlenecks and error rates by tracking requests as they travel through different services.

87. What is the use of Amazon S3 lifecycle policies?

S3 lifecycle policies automate the transition of objects between storage classes (e.g., from Standard to Glacier) or delete them after a specified period. This helps reduce storage costs and manage data retention.

88. What is AWS Security Hub?

AWS Security Hub provides a comprehensive view of your security posture in AWS. It aggregates, organizes, and prioritizes security findings from across AWS services, such as GuardDuty, Inspector, and Macie.

89. What is Amazon SQS FIFO queues?

SQS FIFO (First-In-First-Out) queues ensure that messages are processed in the exact order they are sent and that each message is processed only once.

90. What is the AWS Well-Architected Tool?

The AWS Well-Architected Tool helps you review your workloads against AWS best practices. It provides insights into architecture improvements and helps ensure your applications are secure, reliable, efficient, and cost-effective.

91. What is AWS Batch and how does it work?

AWS Batch enables you to run batch computing workloads on the AWS Cloud. It dynamically provisions the compute resources required for your jobs, handles job queues, and ensures optimal resource utilization.

92. How would you monitor your AWS resources?

AWS resources can be monitored using:

• Amazon CloudWatch for metrics and logs.

• AWS CloudTrail for API call logging.

• AWS X-Ray for application tracing and debugging.

93. How do you integrate AWS with a CI/CD pipeline?

AWS provides services like CodePipeline, CodeBuild, and CodeDeploy for integrating CI/CD. You can automate testing, building, and deploying your Java applications to AWS environments.

94. What is the difference between S3 and EFS?

• S3 is object storage for scalable, low-cost, and highly durable data storage.

• EFS is a file storage system used for scalable and shared file storage that can be mounted by multiple EC2 instances simultaneously.

95. What is the maximum size of an object you can upload to S3?

The maximum size of an individual object you can upload to S3 is 5TB. You can upload larger objects using multipart uploads.

96. What is Amazon CloudWatch Alarms?

CloudWatch Alarms monitor the state of a particular metric and can trigger actions (such as sending notifications via SNS, or auto-scaling actions) when certain thresholds are breached.

97. What is Amazon Elastic Beanstalk Environment?

An Elastic Beanstalk Environment is a container for running your application and includes resources like EC2 instances, RDS databases, and load balancers. It provides simplified deployment and management of applications.

98. How do you handle traffic spikes in AWS?

To handle traffic spikes in AWS, you can use:

• Auto Scaling to scale EC2 instances dynamically.

• Elastic Load Balancers (ELB) to distribute incoming traffic efficiently.

• CloudFront for global content delivery with lower latency.

99. What is Amazon Elastic Inference?

Amazon Elastic Inference provides GPU-powered instances that allow you to attach inference acceleration to EC2 instances, reducing costs for deep learning inference workloads.

100. What is AWS Outposts?

AWS Outposts extends AWS infrastructure, services, APIs, and tools to on-premises locations for a truly hybrid environment. It allows you to run AWS services on-premises with consistent architecture, security, and operational control.

101. What is AWS Elastic Beanstalk, and how does it help developers?

AWS Elastic Beanstalk is a Platform-as-a-Service (PaaS) offering that automatically handles the deployment, scaling, and monitoring of applications. Developers simply need to upload their code, and Beanstalk handles the infrastructure (e.g., EC2 instances, load balancing, scaling).

102. What are the benefits of using AWS Aurora?

Amazon Aurora is a MySQL- and PostgreSQL-compatible relational database service that provides enhanced performance, scalability, and durability. Benefits include automatic backups, replication, and encryption, and it's highly available with up to 15 read replicas.

103. How would you use AWS Lambda with Java?

AWS Lambda supports Java through the AWS SDK for Java. You can write a Lambda function in Java, configure it with an event trigger (e.g., API Gateway, S3 event), and AWS Lambda takes care of provisioning the execution environment and scaling.

104. How do you handle serverless architectures using AWS Lambda?

In a serverless architecture, AWS Lambda runs functions in response to events, and you do not manage the servers directly. You integrate Lambda with other AWS services like API Gateway, DynamoDB, or S3 to process events without worrying about infrastructure scaling or maintenance.

105. What is the difference between AWS Lambda and AWS EC2?

• AWS Lambda is a serverless compute service that runs code in response to events, where you don't need to manage servers or infrastructure.

• AWS EC2 provides virtual machines (VMs) where you have more control over the operating system and can manage resources, but you need to handle scaling and provisioning manually.

106. What is Amazon API Gateway and how does it integrate with AWS Lambda?

Amazon API Gateway is a fully managed service that allows you to create, publish, and manage APIs. You can use it to trigger Lambda functions when API requests are received, allowing you to build serverless applications with Lambda and API Gateway.

107. How do you manage state in a serverless application using AWS Lambda?

AWS Lambda is stateless by nature, but you can manage state by using external storage or databases like DynamoDB, S3, or ElastiCache to store and retrieve state between function invocations.

108. What are Amazon SQS and its use cases in a Java application?

Amazon SQS (Simple Queue Service) is a fully managed message queue service. In a Java application, it can be used to decouple components, manage message-driven workflows, and ensure reliable delivery of messages between microservices.

109. How would you handle message ordering and duplication in Amazon SQS?

• To handle message ordering, use FIFO queues in SQS, which guarantee the order of messages.

• To avoid message duplication, SQS supports deduplication IDs for FIFO queues, ensuring that duplicate messages are not processed.

110. How do you use Amazon S3 in a Java application?

You can interact with Amazon S3 in Java using the AWS SDK for Java. The SDK allows you to upload, download, and manage objects in S3 buckets, as well as configure event notifications and manage storage lifecycle policies.

111. What is AWS CodeDeploy, and how does it help in continuous delivery?

AWS CodeDeploy automates the deployment of applications to various compute services like EC2, Lambda, or on-premises servers. It integrates with CI/CD pipelines to help deploy new versions of Java-based applications seamlessly without downtime.

112. What is the significance of IAM roles for Lambda functions in AWS?

IAM roles for Lambda functions provide the necessary permissions for the Lambda function to interact with other AWS services. For example, a Lambda function may need an IAM role with permissions to access DynamoDB, S3, or other resources.

113. How can you implement a microservices architecture in AWS?

In AWS, you can implement microservices architecture by leveraging:

• Amazon ECS or EKS for container orchestration.

• API Gateway for managing API endpoints.

• Lambda for event-driven functions.

• DynamoDB for scalable, serverless data storage.

• SNS/SQS for decoupling microservices.

114. What is AWS Glue, and how can it be used with Java-based ETL workloads?

AWS Glue is a fully managed ETL (Extract, Transform, Load) service. Java can be used in AWS Glue through custom scripts written in Apache Spark, enabling large-scale data processing and transformation.

115. What is the role of Amazon Elastic File System (EFS) in a Java application?

Amazon EFS is a scalable, shared file storage service that can be used for applications requiring access to shared file systems, such as Java-based applications running on multiple EC2 instances needing common storage.

116. How do you secure Java applications deployed on AWS?

To secure Java applications in AWS:

• Use IAM roles to manage access to AWS resources.

• Enable encryption for sensitive data at rest and in transit.

• Utilize VPC to isolate your application infrastructure.

• Use AWS WAF to protect against common web attacks.

117. What is the best approach for managing configurations in a Java application deployed in AWS?

You can manage configuration settings in a Java application using:

• AWS Systems Manager Parameter Store for storing and retrieving configurations.

• AWS Secrets Manager for managing sensitive information like API keys or database credentials.

• Environment variables in Elastic Beanstalk or Lambda for runtime configuration.

118. What are the key differences between Amazon RDS and Amazon DynamoDB?

• RDS is a managed relational database service that supports SQL-based databases (e.g., MySQL, PostgreSQL).

• DynamoDB is a managed NoSQL database optimized for high-availability, low-latency workloads that do not require relational data models.

119. How do you manage large amounts of unstructured data in AWS using Java?

For large unstructured data, you can use Amazon S3 for storage, integrating with Java applications via the AWS SDK. For big data processing, you can use Amazon EMR or AWS Glue to run ETL jobs on the data.

120. What is Amazon Kinesis, and how can it be integrated with Java-based applications?

Amazon Kinesis is a platform for real-time data streaming and analytics. Java-based applications can send and receive data streams using the Kinesis Client Library (KCL), enabling real-time data processing and analysis.

121. How would you implement a backup and recovery strategy for a Java application using AWS services?

You can implement backup and recovery by:

• Using Amazon RDS automated backups and manual snapshots for relational databases.

• Enabling S3 versioning and using AWS Backup to automate backups of data.

• Configuring Cross-Region Replication in S3 for disaster recovery.

122. How do you handle cross-region replication in AWS?

Cross-region replication can be configured in services like Amazon S3 (for object storage) and RDS (for relational databases). This ensures that data is available in multiple regions for disaster recovery and high availability.

123. What is Amazon CloudFront and how does it benefit Java applications?

Amazon CloudFront is a Content Delivery Network (CDN) that caches copies of your application’s static content (images, videos, scripts) closer to the user. It reduces latency and improves performance, especially for global Java web applications.

124. What are the key benefits of using AWS for Java-based backend development?

The key benefits include:

• Scalability with services like EC2, Lambda, and RDS.

• Security through IAM, VPCs, and encryption features.

• High availability with features like Multi-AZ deployments and load balancing.

• Cost efficiency with pay-as-you-go pricing models and the AWS Free Tier.

• Integration with other AWS services like SQS, SNS, S3, etc.

125. How do you monitor the performance of a Java application running on AWS?

You can monitor Java application performance on AWS using:

• Amazon CloudWatch to track metrics, logs, and custom application metrics.

• AWS X-Ray to trace and analyze application performance and troubleshoot latency issues.

• CloudWatch Alarms to set thresholds and receive notifications for performance anomalies.

126. What is the AWS SDK for Java and how do you use it in backend applications?

The AWS SDK for Java is a set of libraries that allow Java developers to easily integrate with AWS services. It simplifies tasks like managing S3 buckets, interacting with DynamoDB, or managing EC2 instances from within Java applications.