Top 25 AWS Cloud Architect Interview Questions and Answers

AWS, or Amazon Web Services, is a comprehensive cloud computing platform provided by Amazon. It offers a mix of infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS) offerings. AWS allows users to run applications and store data on the cloud, providing scalability, reliability, and flexibility.

For more information, visit the official AWS overview here.

Key components of AWS architecture include:

• Regions and Availability Zones: Geographically isolated locations for data centers.
• VPC (Virtual Private Cloud): A logically isolated section of the AWS cloud.
• EC2 (Elastic Compute Cloud): Virtual servers for running applications.
• S3 (Simple Storage Service): Scalable storage for data.
• RDS (Relational Database Service): Managed relational database service.

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

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

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

Amazon EC2 (Elastic Compute Cloud) is a web service that provides resizable compute capacity in the cloud. Key benefits include:

• Scalability: Easily scale up or down based on demand.
• Cost-Effectiveness: Pay-as-you-go pricing model.
• Flexibility: Choose different instance types based on requirements.
• Integration: Works seamlessly with other AWS services.

AWS VPC (Virtual Private Cloud) allows users to create a logically isolated network in the AWS cloud. Users can define their IP address range, create subnets, configure route tables, and set up network gateways. This provides enhanced security and control over network resources.

AWS IAM (Identity and Access Management) allows you to manage access to AWS services and resources securely. You can create and manage AWS users and groups, and use permissions to allow or deny access to resources. IAM helps in implementing the principle of least privilege.

Learn more about IAM here.

Some AWS security best practices include:

• Use IAM roles instead of access keys for applications.
• Enable MFA (Multi-Factor Authentication) for all users.
• Regularly audit permissions and use least privilege.
• Monitor AWS resources with CloudTrail.
• Encrypt data in transit and at rest.

AWS Lambda is a serverless compute service that runs your code in response to events and automatically manages the compute resources. Use cases include:

• Data processing (e.g., real-time file processing).
• Web application backends.
• Automated workflows.
• IoT backend services.

AWS ensures high availability through:

• Multiple Availability Zones: Applications can be deployed across multiple zones.
• Elastic Load Balancing: Distributes incoming traffic across multiple targets.
• Auto Scaling: Automatically adjusts capacity based on traffic.

AWS CloudFormation is a service that helps you define and provision AWS infrastructure using code. Benefits include:

• Infrastructure as Code: Manage resources in a declarative way.
• Automation: Easily create and update resources.
• Version Control: Keep track of changes in templates.

AWS S3 (Simple Storage Service): Object storage service for storing and retrieving any amount of data.

AWS EBS (Elastic Block Store): Block storage service designed for use with EC2 instances.

S3 is ideal for static content, while EBS is suited for applications requiring frequent read/write operations.

AWS Auto Scaling automatically adjusts the number of EC2 instances in response to demand. It helps maintain application performance and minimize costs by scaling in and out based on defined policies.

The AWS Well-Architected Framework provides best practices to help cloud architects build secure, high-performing, resilient, and efficient infrastructure for applications. It consists of five pillars: Operational Excellence, Security, Reliability, Performance Efficiency, and Cost Optimization.

AWS provides monitoring tools such as:

• Amazon CloudWatch: Monitors AWS resources and applications in real-time.
• AWS CloudTrail: Tracks user activity and API usage.
• AWS Config: Tracks configuration changes to resources.

AWS Route 53 is a scalable and highly available Domain Name System (DNS) web service. It provides DNS routing for applications and can route users to endpoints based on various policies, including latency-based routing and geo-routing.

AWS RDS (Relational Database Service) provides several benefits:

• Automated backups and snapshots.
• Scaling capabilities.
• High availability with Multi-AZ deployments.
• Performance monitoring and tuning.

Public Subnet: A subnet that is accessible from the internet. Resources in public subnets can have public IP addresses.

Private Subnet: A subnet that is not directly accessible from the internet. Resources in private subnets can only be accessed through a VPN or a NAT gateway.

Securing data in AWS can be achieved through:

• Encryption at rest and in transit using AWS KMS (Key Management Service).
• Implementing IAM policies to restrict access.
• Using security groups and network ACLs to control inbound/outbound traffic.

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

AWS Elastic Beanstalk is a PaaS that simplifies deploying and managing applications. It automatically handles the deployment, from capacity provisioning to load balancing and auto-scaling. Developers can focus on writing code without managing the underlying infrastructure.

Multi-tenancy in AWS allows multiple customers (tenants) to share the same infrastructure while keeping their data isolated. This is achieved through logical isolation and security measures, ensuring that one tenant's data is not accessible to others.

AWS provides various disaster recovery strategies, such as:

• Backup and Restore: Regular backups to S3.
• Pilot Light: Keep a minimal version of your environment running.
• Warm Standby: Maintain a scaled-down version of a fully functional environment.
• Multi-Site: Deploy in multiple regions for redundancy.

The AWS Shared Responsibility Model defines the security responsibilities of AWS and the customer. AWS is responsible for the security of the cloud infrastructure, while customers are responsible for securing their data and applications within the cloud.

Learn more about it here.

AWS tags are key-value pairs that help organize and manage AWS resources. Tags allow you to categorize resources by purpose, owner, or environment, enabling better cost management and resource tracking.

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

• Decoupling components of a cloud application.
• Buffering requests to smooth out spikes in traffic.
• Processing messages asynchronously.