AWS Certified Cloud Practitioner (AWS Cloud Practitioner) Interview Questions Answers

AWS Certified Cloud Practitioner (AWS Cloud Practitioner) Interview Questions Answers - For Intermediate

1. What is an S3 bucket?

An S3 bucket is a container for objects stored in Amazon S3. It is similar to a folder in a file system and allows you to store and organize data in the cloud.

2. What is the difference between S3 Standard, S3 Intelligent-Tiering, and S3 Glacier storage classes?

• S3 Standard is suitable for frequently accessed data.
• S3 Intelligent Tiering automatically moves objects between two access tiers based on access patterns.
• S3 Glacier is designed for data archiving and long-term backup at a lower cost.

3. Explain the difference between a public subnet and a private subnet in a VPC.

A public subnet is a subnet that has a route to the Internet gateway, allowing resources within the subnet to communicate directly with the Internet. A private subnet, on the other hand, does not have a route to the internet gateway and relies on a NAT gateway or NAT instance for outbound internet access.

4. What is an EBS volume?

Amazon Elastic Block Store (EBS) provides block-level storage volumes for use with EC2 instances. An EBS volume is a durable, block-level storage device that you can attach to a single EC2 instance.

5. What is a security group?

A security group acts as a virtual firewall for your EC2 instances to control inbound and outbound traffic. You can specify rules that allow traffic to or from specific IP addresses, protocols, and ports.

6. Explain the difference between horizontal scaling and vertical scaling.

• Horizontal scaling (scaling out) involves adding more instances or resources to distribute the workload across multiple machines.
• Vertical scaling (scaling up) involves increasing the capacity of a single machine, such as upgrading CPU, RAM, or storage.

7. What is AWS Lambda?

AWS Lambda is a serverless computing service that lets you run code without provisioning or managing servers. It automatically scales your application by running code in response to triggers and events.

8. What is CloudFront?

Amazon CloudFront is a content delivery network (CDN) service that delivers data, videos, applications, and APIs to users with low latency and high transfer speeds. It caches content at edge locations around the world for faster delivery to end-users.

9. What is an AMI?

An Amazon Machine Image (AMI) is a template that contains the software configuration (operating system, application server, and applications) required to launch an EC2 instance. You can launch instances from pre-built AMIs or create your own custom AMIs.

10. What is AWS KMS?

AWS Key Management Service (KMS) is a managed service that allows you to create and control the encryption keys used to encrypt your data. It integrates with other AWS services to help you protect sensitive data.

11. Explain the difference between synchronous and asynchronous communication.

• Synchronous communication occurs when the sender and receiver are active at the same time and wait for each other's response.
• Asynchronous communication allows the sender to proceed immediately after sending a message, without waiting for a response from the receiver.

12. What is the purpose of AWS CloudTrail?

AWS CloudTrail records API calls made on your AWS account and delivers log files containing information about those calls. It helps you track changes to resources, troubleshoot operational issues, and meet compliance requirements.

13. What is the difference between encryption in transit and encryption at rest?

• Encryption in transit refers to the encryption of data while it is being transmitted between two endpoints, ensuring that it cannot be intercepted or tampered with during transmission.
• Encryption at rest refers to the encryption of data while it is stored on a disk or in a database, protecting it from unauthorized access even if the storage media is stolen or compromised.

14. What is AWS Elastic Beanstalk?

AWS Elastic Beanstalk is a platform as a service (PaaS) that simplifies the deployment and management of applications in the AWS cloud. It automatically handles the deployment, capacity provisioning, load balancing, and scaling of your application.

15. What is AWS CloudFormation template?

An AWS CloudFormation template is a JSON or YAML formatted text file that describes the AWS resources and their properties needed to run an application. It allows you to define and provision AWS infrastructure as code.

AWS Certified Cloud Practitioner (AWS Cloud Practitioner) Interview Questions Answers - For Advanced

1. What are the key components of AWS IAM (Identity and Access Management), and how do they contribute to securing cloud resources?

AWS IAM includes users, groups, roles, and policies to control access to AWS resources. Users represent individuals, groups are collections of users, roles are meant for temporary access, and policies define permissions for each entity. The IAM helps secure AWS resources by enabling fine-grained control over who can access resources and what actions they can perform. For example, a policy can restrict access to specific S3 buckets or limit EC2 instance launching to specific users. The best practice is to implement the principle of least privilege, ensuring users only have the necessary permissions.

2. How does Amazon EC2 Auto Scaling help in managing cost efficiency and high availability?

Amazon EC2 Auto Scaling automatically adjusts the number of EC2 instances to match the current demand, ensuring high availability while optimizing costs. When traffic increases, Auto Scaling adds more instances to handle the load. When demand decreases, it terminates unneeded instances, thus reducing costs. For example, in a web application scenario, Auto Scaling will automatically add or remove instances during traffic spikes or quiet periods, ensuring the application is always responsive but without incurring unnecessary expenses.

3. Can you explain how AWS Global Accelerator enhances the performance and availability of your applications?

AWS Global Accelerator is a networking service that improves the availability and performance of applications with global users by routing traffic through the AWS global network infrastructure. It provides two static IP addresses that act as a fixed entry point for your application, reducing latency by directing users to the optimal AWS endpoint based on geolocation and health checks. This also mitigates the risks of IP address changes affecting the application's DNS configuration and improves failover times when an endpoint becomes unhealthy.

4. How does Amazon CloudFront work, and what are some use cases where you would apply it?

Amazon CloudFront is a content delivery network (CDN) that delivers data, videos, applications, and APIs to users globally with low latency and high transfer speeds. It works by caching content in edge locations worldwide, bringing content closer to users. CloudFront is commonly used for serving static websites, video streaming, software distribution, and protecting APIs. One key feature is its integration with AWS Shield for DDoS protection, making it ideal for use cases that require both speed and security, like e-commerce websites or media-heavy applications.

5. What is AWS Lambda, and how can you optimize its performance and cost efficiency?

AWS Lambda is a serverless computing service that automatically runs code in response to triggers and manages the underlying infrastructure. You can optimize Lambda performance by managing memory allocation, keeping the code lightweight, reducing cold start times with provisioned concurrency, and ensuring optimal packaging by limiting dependencies. Cost efficiency can be improved by right-sizing the memory allocation to balance performance with cost. For example, allocating higher memory increases CPU, which might reduce the execution time, lowering the overall cost for compute time charged by Lambda.

6. How does AWS VPC peering work, and what are the security considerations?

AWS VPC peering allows direct communication between two VPCs, either in the same AWS account or across different accounts, using private IP addresses. Security considerations include proper route configuration, applying network ACLs and security groups to control the traffic between peered VPCs, and ensuring that sensitive data is protected by encrypting the traffic using services like AWS Key Management Service (KMS). It is important to note that VPC peering does not allow transitive peering, so you need to set up individual peering connections if communication is required between multiple VPCs.

7. What is an AWS Transit Gateway, and how is it different from VPC peering?

AWS Transit Gateway is a highly scalable and managed router for connecting multiple VPCs, on-premises networks, and VPNs. Unlike VPC peering, which establishes a one-to-one connection between two VPCs, a Transit Gateway allows you to centralize and manage the connectivity for multiple VPCs in a hub-and-spoke architecture. It simplifies network management, especially in large, multi-VPC environments, as it provides transitive routing across VPCs and on-premises networks without requiring individual peering connections for each VPC pair.

8. How does AWS S3 lifecycle management work, and how can it reduce storage costs?

AWS S3 lifecycle management automatically transitions objects between storage classes based on pre-defined rules, optimizing cost by storing objects in the most cost-effective class. For example, frequently accessed data can be stored in S3 Standard, while infrequently accessed data can be moved to S3 Infrequent Access (IA), and archival data can be transitioned to Glacier. You can also set rules to delete objects after a certain time to free up space, thereby further reducing costs. Lifecycle policies ensure efficient data management over time, particularly in large-scale storage environments.

9. How do you secure data at rest and in transit in AWS?

Data at rest can be secured using encryption methods like AWS Key Management Service (KMS), which enables encryption of data in S3, RDS, EBS, and other AWS services. In transit, data can be secured by using SSL/TLS protocols for communication between clients and AWS resources. AWS also offers additional encryption services like AWS Certificate Manager (ACM) for managing SSL/TLS certificates. Combining both encryption at rest and in transit ensures that sensitive data is protected from unauthorized access throughout its lifecycle.

10. Explain the concept of AWS Organizations and how you would manage multi-account governance.

AWS Organizations enables centralized management of multiple AWS accounts in a hierarchical structure. You can create an organization and add accounts under Organizational Units (OUs) to apply policies and manage governance at scale. Service Control Policies (SCPs) allow fine-grained control over account permissions, enforcing security, compliance, and cost-management policies across all accounts in the organization. AWS Organizations is especially useful for large enterprises to maintain security baselines and ensure that accounts comply with company policies.

11. What is AWS Direct Connect, and how does it differ from a VPN connection?

AWS Direct Connect provides a dedicated network connection between your on-premises data center and AWS, offering high bandwidth, low latency, and reliable performance. Unlike a VPN, which uses the public internet and is more susceptible to latency and variability, Direct Connect provides a private, secure connection that doesn’t traverse the public internet. This is ideal for workloads requiring consistent, high-performance connections such as large-scale data transfers, real-time applications, or hybrid cloud architectures.

12. What is Amazon EFS, and how does it compare to Amazon S3 and Amazon EBS?

Amazon Elastic File System (EFS) is a scalable file storage system designed for use with AWS services and on-premises resources. Unlike Amazon S3, which is object storage, EFS is file storage, making it suitable for applications that require hierarchical organization and file-level access. EBS, on the other hand, is block storage designed for use with EC2 instances. While EFS supports multiple EC2 instances accessing the same files concurrently, EBS provides dedicated block-level storage for a single instance. EFS is ideal for workloads like content management, web serving, and big data applications.

13. How does AWS Route 53 achieve global scalability and low-latency routing?

AWS Route 53 is a highly scalable Domain Name System (DNS) web service that offers low-latency routing by leveraging a global network of DNS servers distributed across AWS regions. It uses routing policies like Geolocation, Latency-based, and Weighted Routing to direct traffic to the nearest or optimal resources based on user location or health checks. Route 53 integrates with AWS health checks to ensure high availability by automatically directing traffic away from unhealthy endpoints.

14. How does AWS CloudFormation manage infrastructure as code (IaC), and what are the benefits?

AWS CloudFormation allows you to define your infrastructure as code using JSON or YAML templates. These templates describe all the AWS resources needed for your application, such as EC2 instances, VPCs, or RDS databases, and CloudFormation provisions, and configure them automatically. This ensures consistency across environments, reduces human error, and allows for version control of infrastructure. IaC facilitates the automation of complex cloud environments, making scaling and disaster recovery more efficient.

15. Can you explain the AWS Well-Architected Framework and how it contributes to building secure, efficient, and cost-effective architectures?

The AWS Well-Architected Framework consists of five pillars: Operational Excellence, Security, Reliability, Performance Efficiency, and Cost Optimization. It provides best practices and guidelines for designing secure, high-performing, resilient, and efficient cloud infrastructures. For example, under the Security pillar, practices such as enabling encryption and using IAM roles are emphasized. The framework helps organizations review their architectures, identify potential risks, and ensure that their workloads are aligned with best practices to optimize performance and costs while maintaining security and compliance.