Top 22+ AWS Interview Questions and Answers for 2021

Here are some common AWS interview questions and answers:

What is AWS?

AWS stands for Amazon Web Services. It is a subsidiary of Amazon providing on-demand cloud computing platforms and APIs to individuals, companies, and governments.

What are the core components of AWS?

AWS includes a wide range of services, but the core components include Compute, Storage, Databases, Networking, and Content Delivery.

What is EC2?

Amazon Elastic Compute Cloud (EC2) is a web service that provides resizable compute capacity in the cloud. It allows users to run virtual servers, known as instances.

Explain the difference between S3 and EBS.

Amazon S3 is object storage used for storing and retrieving files, while Amazon EBS (Elastic Block Store) is a block storage used for attaching to EC2 instances.

What is the AWS Free Tier?

The AWS Free Tier is a program that offers limited free usage of AWS services for 12 months, allowing users to explore and try out various AWS services.

What is VPC?

Amazon Virtual Private Cloud (VPC) is a virtual network dedicated to your AWS account. It allows you to launch AWS resources into a virtual network that you’ve defined.

What is AWS Lambda?

AWS Lambda is a serverless compute service that allows you to run code in response to events and automatically manage the computing resources required by that code.

Explain the difference between RDS and DynamoDB.

Amazon RDS is a managed relational database service, while Amazon DynamoDB is a managed NoSQL database service.

What is an AMI?

An Amazon Machine Image (AMI) is a pre-configured virtual machine that is used to create EC2 instances.

What is auto-scaling in AWS?

Auto-scaling is a service that automatically adjusts the number of EC2 instances in a group to maintain application performance and availability.

What is CloudWatch?

Amazon CloudWatch is a monitoring and observability service that provides data and actionable insights for AWS resources.

What is the AWS Shared Responsibility Model?

The Shared Responsibility Model outlines the division of security responsibilities between AWS and the customer, with AWS responsible for the infrastructure’s security and customers responsible for their data and application security.

What is AWS Snowball, and in what scenarios is it used?

AWS Snowball is a physical data transport service used to transfer large amounts of data into and out of AWS. It’s typically used when transferring data over the internet is impractical due to the volume of data.

Explain what AWS Lambda Layers are and how they can be beneficial in serverless applications.

AWS Lambda Layers allow you to centrally manage code and data that is shared across multiple Lambda functions. They can be useful for code reuse and reducing redundancy in serverless applications.

What is the difference between Amazon SNS and Amazon SQS?

Amazon Simple Notification Service (SNS) is a pub/sub messaging service, while Amazon Simple Queue Service (SQS) is a distributed message queuing service. SNS is used for push notifications, while SQS is used for decoupled, distributed systems.

How can you secure your S3 buckets from unauthorized access?

You can secure S3 buckets by configuring bucket policies, Access Control Lists (ACLs), and using AWS Identity and Access Management (IAM) to control access. Additionally, you can enable S3 bucket logging to monitor access.

Explain the use of AWS Identity and Access Management (IAM) roles and when you might use them.

IAM roles are used to grant permissions to AWS services, EC2 instances, or Lambda functions without the need for access keys. They are commonly used for applications running on EC2 instances or Lambda functions that need to access AWS services securely.

What is Amazon VPC Peering, and what are its limitations?

VPC peering allows you to connect two Amazon VPCs so that instances in those VPCs can communicate with each other. Limitations include non-transitive peering, IP range overlap restrictions, and no support for transitive routing.

What is the AWS Well-Architected Framework, and how does it benefit AWS customers?

The AWS Well-Architected Framework provides best practices for building secure, high-performing, resilient, and efficient infrastructure for applications. It helps AWS customers design and operate reliable, secure, and efficient systems.

Explain what AWS CloudFormation is and how it helps with infrastructure as code (IAC).

AWS CloudFormation is a service that allows you to define your infrastructure as code using templates. It enables you to provision and manage AWS resources in a consistent and automated manner.

What is the difference between AWS CodeBuild and AWS CodePipeline?

AWS CodeBuild is a fully managed build service for compiling source code and running tests, while AWS CodePipeline is a continuous integration and continuous delivery (CI/CD) service that orchestrates the release process.

What is AWS Kinesis, and how is it used for real-time data streaming?

Amazon Kinesis is a platform for streaming data on AWS. It is used to collect, process, and analyze real-time data streams from various sources, such as sensors, log files, and social media.