Interview Questions and Answers for the AWS Certified Solutions Architect – Associate exam

Here is a list of some common questions and their answers to help you prepare for interviews related to this certification

What are the key components of AWS architecture?

Answer: Some key components of AWS architecture include Amazon S3 (Simple Storage Service), Amazon EC2 (Elastic Compute Cloud), Amazon VPC (Virtual Private Cloud), Amazon RDS (Relational Database Service), AWS Lambda, and Amazon CloudFront.

What is the difference between auto-scaling and load balancing in AWS?

Answer: Auto-scaling is a service that automatically adjusts the number of EC2 instances based on the demand or load on the system. Load balancing, on the other hand, is a technique used to distribute the incoming traffic across multiple instances evenly, ensuring that no single instance is overwhelmed.

Explain the difference between Amazon S3 and Amazon EBS.

Answer: Amazon S3 (Simple Storage Service) is an object storage service, primarily used for storing and retrieving large amounts of unstructured data, like images, videos, or log files. Amazon EBS (Elastic Block Store) is a block-level storage service, used as persistent storage for Amazon EC2 instances. EBS is suitable for workloads that require low-latency access and consistent performance, like databases or applications.

What is the difference between a security group and a network access control list (NACL) in AWS?

Answer: Security groups are virtual firewalls that act at the instance level, controlling inbound and outbound traffic for EC2 instances. Network Access Control Lists (NACLs) are stateless firewalls that control inbound and outbound traffic at the subnet level within a VPC.

What is the difference between AWS Lambda and Amazon EC2?

Answer: AWS Lambda is a serverless compute service that allows you to run your code without provisioning or managing servers. Lambda automatically scales your applications in response to the number of triggers, charging you only for the actual compute time. Amazon EC2 is a scalable compute service that allows you to run virtual machines in the cloud. With EC2, you have more control over the underlying infrastructure and can customize your instances with specific configurations.

What is Amazon RDS, and what are its benefits?

Answer: Amazon RDS (Relational Database Service) is a managed database service that simplifies the process of setting up, operating, and scaling a relational database in the cloud. Benefits of Amazon RDS include automated backups, patch management, automatic scaling, and high availability through multi-AZ deployments.

What is Amazon CloudFront, and what are its main features?

Answer: Amazon CloudFront is a global content delivery network (CDN) service that securely delivers data, videos, applications, and APIs to users worldwide with low latency and high transfer speeds. Main features of CloudFront include caching content at edge locations, DDoS protection, integration with AWS services like S3 and [email protected], and support for custom SSL certificates.

Explain the difference between Amazon S3 One Zone-Infrequent Access and S3 Reduced Redundancy Storage.

Answer: Amazon S3 One Zone-Infrequent Access (S3 One Zone-IA) stores data in a single availability zone and is designed for infrequently accessed data that can be recreated if lost. It is a cost-effective storage option for backups, disaster recovery data, or secondary copies. S3 Reduced Redundancy Storage (RRS) is a deprecated storage class that was designed to store non-critical, reproducible data at lower levels of redundancy than the standard S3 storage class.

What are the main differences between Amazon Aurora and Amazon RDS?

Answer: Amazon Aurora is a managed relational database service compatible with MySQL and PostgreSQL. It is a part of Amazon RDS, but it is specifically designed for better performance, availability, and scalability compared to traditional RDS instances. Aurora offers features such as automatic storage scaling, up to 15 read replicas, continuous backups, and multi-AZ deployments.

What is Amazon VPC, and what are its main components?

Answer: Amazon VPC (Virtual Private Cloud) is a service that allows you to create an isolated, virtual network within the AWS cloud to deploy your resources securely. Main components of a VPC include subnets, route tables, network access control lists (NACLs), security groups, internet gateways, NAT gateways, and VPC endpoints.

Explain the difference between Amazon SQS and Amazon SNS.

Answer: Amazon SQS (Simple Queue Service) is a managed message queuing service that enables decoupling and communication between distributed components in a cloud application. It supports both standard and FIFO queues. Amazon SNS (Simple Notification Service) is a managed messaging service that supports pub/sub messaging patterns and fan-out architecture, allowing you to send messages to multiple subscribers, such as email, SMS, or Lambda functions.

What is AWS Elastic Beanstalk, and what are its benefits?

Answer: AWS Elastic Beanstalk is a fully managed service that simplifies the deployment, management, and scaling of applications in various languages, including Java, .NET, PHP, Node.js, Python, Ruby, and Go. Benefits of Elastic Beanstalk include automatic provisioning of resources, simplified application deployment using pre-configured environments, and automatic monitoring and health management of applications.

What is the difference between a stateful and stateless firewall in AWS?

Answer: A stateful firewall, like AWS security groups, maintains the context of connections and allows or denies traffic based on connection state information. It automatically allows return traffic for established connections without the need for explicit rules. A stateless firewall, like AWS network access control lists (NACLs), does not maintain connection state information and requires separate rules for inbound and outbound traffic.

What is the AWS Shared Responsibility Model?

Answer: The AWS Shared Responsibility Model is a security and compliance framework that defines the responsibilities of AWS and the customer in maintaining the security of cloud services and applications. AWS is responsible for the security “of” the cloud, including the infrastructure, hardware, software, and networking components. The customer is responsible for security “in” the cloud, including data encryption, application security, identity and access management, and network traffic protection.

What is the difference between AWS Organizations and AWS Resource Access Manager (RAM)?

Answer: AWS Organizations is a service that allows you to centrally manage and consolidate multiple AWS accounts within a single organization, enabling you to apply policies, create consolidated billing, and provide access control across accounts. AWS Resource Access Manager (RAM) is a service that enables you to share your resources, such as subnets, Transit Gateways, or AWS License Manager configurations, with other AWS accounts or within your organization.

Explain Amazon S3 Transfer Acceleration.

Answer: Amazon S3 Transfer Acceleration is a feature that enables fast, easy, and secure transfers of files over long distances between your client and your Amazon S3 bucket. It utilizes Amazon CloudFront’s globally distributed edge locations to accelerate the upload and download of data by routing traffic through the AWS backbone network, improving performance, especially for users located far from the bucket’s region.

What are AWS IAM roles, and why are they important?

Answer: AWS IAM roles are a set of permissions that define what actions are allowed and denied by an AWS service or entity. IAM roles are important because they provide a secure way to grant permissions to AWS services, like EC2 instances or Lambda functions, to access other AWS resources without using long-term access keys. Roles can be assumed by AWS services, federated users, or other AWS accounts, allowing you to delegate access to resources while maintaining the principle of least privilege.

What are AWS placement groups, and what are the different types of placement groups?

Answer: AWS placement groups are a logical grouping of instances within a single Availability Zone, used to control the placement strategy and network performance of instances. There are three types of placement groups:

• Cluster placement groups: Instances are packed closely together in a low-latency group, suitable for high-performance computing and low-latency applications.
• Partition placement groups: Instances are spread across partitions, providing fault tolerance and improved performance for large-scale distributed applications.
• Spread placement groups: Instances are placed on distinct underlying hardware, reducing correlated failures and suitable for a small number of critical instances.

What is Amazon ElastiCache, and what are its benefits?

Amazon ElastiCache is a fully managed in-memory caching service that improves the performance of web applications by allowing you to retrieve information from fast, managed, in-memory caches, instead of relying on slower disk-based databases. ElastiCache supports popular caching engines like Redis and Memcached. Benefits of ElastiCache include faster data access, improved application performance, ease of setup and management, and automatic scaling and failure recovery.

What are the different types of Amazon EBS volumes?

There are four types of Amazon EBS volumes:

• General Purpose SSD (gp2 and gp3): Balanced price and performance, suitable for a broad range of workloads.
• Provisioned IOPS SSD (io1 and io2): Designed for I/O-intensive workloads, such as databases, that require high performance and low latency.
• Throughput Optimized HDD (st1): Designed for throughput-intensive workloads that require high sequential read and write access, such as big data and log processing.
• Cold HDD (sc1): Designed for less frequently accessed, throughput-intensive workloads, offering the lowest cost per gigabyte.

What is the difference between Amazon S3 and Amazon Glacier?

Amazon S3 is an object storage service designed for storing and retrieving large amounts of unstructured data, like images, videos, or log files. Amazon Glacier is a low-cost, long-term storage service designed for data archiving and long-term backups, with retrieval times ranging from minutes to hours. Amazon S3 is suitable for frequently accessed data, while Amazon Glacier is used for infrequently accessed data that can tolerate longer retrieval times.

How does AWS KMS work, and what are its main features?

AWS Key Management Service (KMS) is a managed service that makes it easy to create and manage cryptographic keys and control their use across a wide range of AWS services and applications. Main features of AWS KMS include centralized key management, integration with other AWS services, key rotation, audit logging, and support for customer-managed keys (CMKs) and imported key material. AWS KMS helps you meet security and compliance requirements by allowing you to protect sensitive data using encryption.

What is AWS WAF, and how does it work?

AWS WAF (Web Application Firewall) is a security service that helps protect your web applications from common web exploits, such as SQL injection, cross-site scripting (XSS), and DDoS attacks. AWS WAF allows you to create custom rules that define which traffic to allow or block, enabling you to safeguard your applications and ensure their availability. AWS WAF can be integrated with Amazon CloudFront, the Application Load Balancer (ALB), and AWS App Runner, providing comprehensive protection for your web applications.

What is the purpose of Amazon Route 53, and what are its main features?

Amazon Route 53 is a highly available and scalable Domain Name System (DNS) web service that provides domain registration, DNS routing, and health checking of resources. Main features of Route 53 include domain registration, routing policies, latency-based routing, geolocation routing, and DNS failover. Route 53 is designed to provide fast, reliable, and secure routing of end-users to your applications and resources.

Explain the difference between AWS CloudFormation and AWS Elastic Beanstalk.

AWS CloudFormation is an Infrastructure as Code (IaC) service that allows you to model, provision, and manage AWS resources using template files. It provides a consistent, repeatable, and version-controlled way of creating and updating your infrastructure. AWS Elastic Beanstalk is a fully managed service that simplifies the deployment, management, and scaling of applications in various languages, including Java, .NET, PHP, Node.js, Python, Ruby, and Go. Elastic Beanstalk automatically provisions resources, deploys applications, and manages the underlying infrastructure, enabling you to focus on writing code.

What is Amazon EFS, and how does it differ from Amazon EBS?

Amazon EFS (Elastic File System) is a managed file storage service that can be mounted onto multiple Amazon EC2 instances or other AWS services, providing a shared file system for your applications. EFS supports the Network File System (NFS) protocol and is designed to be highly available, durable, and scalable. Amazon EBS (Elastic Block Store) is a block-level storage service used as persistent storage for Amazon EC2 instances. EBS is suitable for workloads that require low-latency access and consistent performance, like databases or applications. The main difference between EFS and EBS is that EFS provides a shared file system that can be accessed by multiple instances, while EBS volumes are attached to a single instance.

How do you monitor AWS resources and services?

AWS provides various tools and services for monitoring resources and services, including:

• Amazon CloudWatch: A monitoring service that collects and tracks metrics, logs, and events from AWS resources and applications. CloudWatch can be used to set alarms, visualize logs and metrics, and automate actions based on predefined thresholds.
• AWS X-Ray: A distributed tracing service that provides end-to-end visibility into requests and helps you identify performance bottlenecks, errors, and anomalies in your applications.
• AWS Trusted Advisor: A service that provides best practices and recommendations for optimizing your AWS resources, including cost, performance, security, and fault tolerance.
• AWS Config: A service that tracks changes to your AWS resources and provides a detailed view of your infrastructure configuration over time.

What are the different types of load balancers in AWS, and how do they differ?

There are three types of load balancers in AWS:

• Application Load Balancer (ALB): A layer 7 load balancer that routes HTTP/HTTPS traffic based on the content of the request, such as the URL path or the host field. ALB is suitable for microservices or container-based architectures and supports advanced routing, SSL offloading, and WebSocket protocols.
• Network Load Balancer (NLB): A layer 4 load balancer that routes TCP/UDP traffic based on IP protocol data. NLB is designed for high-performance applications and provides ultra-low latency, preserving the source IP of the clients, and supporting millions of requests per second.
• Classic Load Balancer (CLB): A legacy load balancer that operates at both layer 4 and layer 7, routing traffic based on IP protocol data or application-level information. CLB is suitable for simple load balancing of EC2 instances but has fewer features compared to ALB and NLB.

What is AWS Auto Scaling, and what are its benefits?

AWS Auto Scaling is a service that automatically adjusts the number of compute resources, such as EC2 instances or containers, based on the real-time demand and predefined scaling policies. Benefits of AWS Auto Scaling include:

• Improved application availability: Auto Scaling ensures that your applications have the required capacity to handle varying workloads, providing better performance and user experience.
• Cost optimization: Auto Scaling helps you reduce costs by automatically scaling down resources during periods of low demand and scaling up resources when demand increases.
• Automated management: Auto Scaling simplifies the process of managing compute resources by automatically adjusting capacity based on predefined policies and thresholds.

What is AWS Lambda, and what are its main features?

AWS Lambda is a serverless compute service that lets you run your code without provisioning or managing servers. You can build and run applications and services in response to events, such as changes to data in Amazon S3, updates in Amazon DynamoDB, or custom events from applications or devices. Main features of AWS Lambda include:

• Automatic scaling: Lambda automatically scales your applications based on the number of incoming events, without any manual intervention.
• Pay-per-use pricing: With Lambda, you only pay for the compute time you consume, eliminating the need for pre-allocated or reserved capacity.
• Event-driven architecture: Lambda supports a variety of event sources, allowing you to build event-driven applications that respond to changes in data or user actions.
• Integration with other AWS services: Lambda integrates with various AWS services, such as Amazon S3, Amazon DynamoDB, Amazon API Gateway, and AWS Step Functions, enabling you to build complex applications and workflows.