Java Developers working with AWS (Amazon Web Services) need to be proficient not only in Java programming but also in cloud concepts, AWS services, and best practices for deploying and managing applications on AWS. Below are 25 commonly asked Java Developer AWS interview questions along with answers to help you prepare.

Q1. What is AWS and why is it used?

AWS is a cloud computing platform offering various services like computing power, storage, and databases on demand. It helps developers deploy and scale applications without managing physical servers.

Q2. What AWS services are commonly used by Java developers?

Amazon EC2, S3, RDS, Lambda, Elastic Beanstalk, CloudFormation, and DynamoDB are some commonly used services.

Q3. What is AWS Elastic Beanstalk?

Elastic Beanstalk is a Platform-as-a-Service (PaaS) that lets you deploy and manage applications quickly without managing the underlying infrastructure.

Q4. How do you deploy a Java application on AWS Elastic Beanstalk?

You package your Java app as a WAR or JAR file and upload it via the AWS Management Console, CLI, or IDE plugins. Elastic Beanstalk automatically handles provisioning, load balancing, scaling, and monitoring.

Q5. What is Amazon EC2?

EC2 provides resizable virtual servers in the cloud, allowing you to run applications with full control over operating system and software configuration.

Q6. How can you connect a Java application to Amazon RDS?

Using standard JDBC drivers and connection strings configured with RDS endpoint, username, and password.

Q7. What is AWS Lambda, and how can Java be used with it?

AWS Lambda lets you run code without provisioning servers. Java code can be uploaded as a Lambda function, triggered by events like HTTP requests or S3 uploads.

Q8. How do you manage security for Java applications in AWS?

Using IAM roles and policies, encrypting data at rest and in transit, and securing credentials with AWS Secrets Manager or Parameter Store.

Q9. What is Amazon S3, and how can Java interact with it?

S3 is AWS’s object storage service. Java applications can use the AWS SDK to upload, download, and manage files in S3 buckets.

Q10. What is the AWS SDK for Java?

A collection of libraries and tools for Java developers to interact programmatically with AWS services.

Q11. What are IAM roles, and why are they important?

IAM roles grant temporary permissions to AWS resources without sharing long-term credentials, improving security and access control.

Q12. How do you configure AWS credentials in a Java application?

By using AWS credentials files, environment variables, or IAM roles attached to EC2 instances or Lambda functions.

Q13. What is the difference between vertical and horizontal scaling in AWS?

Vertical scaling means increasing resources of a single instance (CPU, RAM), while horizontal scaling means adding more instances to distribute load.

Q14. What is Amazon DynamoDB, and how is it used with Java?

DynamoDB is a fully managed NoSQL database. Java SDK allows performing CRUD operations and querying DynamoDB tables.

Q15. How do you handle environment-specific configuration in AWS?

Using AWS Systems Manager Parameter Store, environment variables, or configuration files managed per environment.

Q16. What is CloudFormation?

CloudFormation is an Infrastructure as Code (IaC) service that lets you provision AWS resources using JSON or YAML templates.

Q17. How does AWS CloudWatch help Java developers?

CloudWatch monitors application logs, metrics, and events to help diagnose issues and maintain performance.

Q18. What is an Amazon VPC?

Virtual Private Cloud (VPC) is a logically isolated section of the AWS cloud where you can launch AWS resources in a virtual network you define.

Q19. How can you secure communication between Java applications and AWS services?

By using SSL/TLS encryption, signing requests with AWS Signature Version 4, and using secure tokens for authentication.

Q20. What is AWS Auto Scaling?

Auto Scaling automatically adjusts the number of EC2 instances based on demand to maintain performance and reduce costs.

Q21. How do you monitor the health of your Java application on AWS?

Using CloudWatch metrics, application logs, health checks, and AWS X-Ray for tracing.

Q22. What are some best practices for deploying Java applications on AWS?

Use automation tools, handle secrets securely, optimize for scalability, monitor performance, and keep dependencies updated.

Q23. What is AWS CodeDeploy?

A service that automates code deployments to EC2 instances, Lambda functions, or on-premises servers.

Q24. How do you implement logging in a Java AWS Lambda function?

Using the AWS Lambda logger or integrating with CloudWatch Logs to capture and monitor function logs.

Q25. What is the role of Amazon SNS in Java applications?

Amazon Simple Notification Service (SNS) enables sending notifications or messages between distributed systems, which Java applications can publish or subscribe to.