SAP-C02 Amazon Web Services AWS Certified Solutions Architect - Professional Free Practice Exam Questions (2026 Updated)

The correct answer is B. The requirement is resource-side protection for all current and future private Amazon ECR repositories across the organization. AWS Organizations resource control policies are designed to centrally restrict permissions on resources in member accounts and are appropriate when external principals must be prevented from accessing organization-owned resources. AWS documentation lists Amazon Elastic Container Registry as a supported service for RCPs. A condition such as aws:PrincipalOrgID enforces that only principals from the same AWS Organization can access the resources. SCPs restrict principals in accounts, not resource exposure to external principals. Modifying IAM policies in hundreds of accounts is operationally poor and does not protect future repository policies consistently. AWS RAM is not the right control plane for private ECR repository access. (AWS Documentation)

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AWS Control Tower provides a set of " strongly recommended guardrails " that can be enabled to implement governance and policy enforcement. One of these guardrails is " Encrypt Amazon RDS instances " which will detect RDS DB instances that are not encrypted at rest. By enabling this guardrail and applying it to the production OU, the company will be able to enforce encryption for RDS instances in the production environment.

The company should purchase the same Reserved Instances for an additional 3-year term with All Upfront payment. The company should purchase a 3-year Compute Savings Plan with All Upfront payment in the management account to cover any additional compute costs. This solution will provide the company with the most cost savings because Reserved Instances and Savings Plans are both pricing models that offer significant discounts compared to On-Demand pricing. Reserved Instances are commitments to use a specific instance type and size in a single Region for a one- or three-year term. You can choose between three payment options: No Upfront, Partial Upfront, or All Upfront. The more you pay upfront, the greater the discount1. Savings Plans are flexible pricing models that offer low prices on EC2 instances, Fargate, and Lambda usage, in exchange for a commitment to a consistent amount of usage (measured in $/hour) for a one- or three-year term. You can choose between two types of Savings Plans: Compute Savings Plans and EC2 Instance Savings Plans. Compute Savings Plans apply to any EC2 instance regardless of Region, instance family, operating system, or tenancy, including those that are part of EMR, ECS, or EKS clusters, or launched by Fargate or Lambda. EC2 Instance Savings Plans apply to a specific instance family within a Region and provide the most savings2. By purchasing the same Reserved Instances for an additional 3-year term with All Upfront payment, the company can lock in the lowest possible price for its EC2 instances that run continuously for 3 years. By purchasing a 3-year Compute Savings Plan with All Upfront payment in the management account, the company can benefit from additional discounts on any other compute usage across its member accounts.

The other options are not correct because:

Purchasing a 1-year Compute Savings Plan with No Upfront payment in each member account would not provide as much cost savings as purchasing a 3-year Compute Savings Plan with All Upfront payment in the management account. A 1-year term offers lower discounts than a 3-year term, and a No Upfront payment option offers lower discounts than an All Upfront payment option. Also, purchasing a Savings Plan in each member account would not allow the company to share the benefits of unused Savings Plan discounts across its organization.

Purchasing a 3-year EC2 Instance Savings Plan with No Upfront payment in the management account to cover EC2 costs in each AWS Region would not provide as much cost savings as purchasing Reserved Instances for an additional 3-year term with All Upfront payment. An EC2 Instance Savings Plan offers lower discounts than Reserved Instances for the same instance family and Region. Also, a No Upfront payment option offers lower discounts than an All Upfront payment option.

Purchasing a 3-year EC2 Instance Savings Plan with All Upfront payment in each member account would not provide as much flexibility or cost savings as purchasing a 3-year Compute Savings Plan with All Upfront payment in the management account. An EC2 Instance Savings Plan applies only to a specific instance family within a Region and does not cover Fargate or Lambda usage. Also, purchasing aSavings Plan in each member account would not allow the company to share the benefits of unused Savings Plan discounts across its organization.

Option C is correct because using Auto Scaling groups for the backend services allows the company to scale up or down the number of EC2 instances based on the demand and traffic. This way, the backend services can handle more requests during peak seasons without compromising performance or availability. Using DynamoDB auto scaling allows the company to adjust the provisioned read and write capacity of the table or index automatically based on the actual traffic patterns. This way, the table or index can handle sudden increases or decreases in workload without throttling or overprovisioning1.

Option A is incorrect because migrating the backend services to AWS Lambda may require significant development effort to rewrite the code and test the functionality. Moreover, increasing the read and write capacity of DynamoDB manually may not be efficient or cost-effective, as it does not account for the variability of the workload. The company may end up paying for unused capacity or experiencing throttling if the workload exceeds the provisioned capacity1.

Option B is incorrect because migrating the backend services to AWS Lambda may require significant development effort to rewrite the code and test the functionality. Moreover, configuring DynamoDB to use global tables may not be necessary or beneficial for the company, as global tables are mainly used for replicating data across multiple AWS Regions for fast local access and disaster recovery. Global tables do not automatically scale the provisioned capacity of each replica table; they still require manual or auto scaling settings2.

Option D is incorrect because using Amazon Simple Queue Service (Amazon SQS) and an AWS Lambda function to write to DynamoDB may introduce additional complexity and latency to the application architecture. Amazon SQS is a message queue service that decouples and coordinates the components of a distributed system. AWS Lambda is a serverless compute service that runs code in response to events. Using these services may require significant development effort to integrate them with the backend services and DynamoDB. Moreover, they may not improve the read performance of DynamoDB, which may also be affected by high traffic3.

Auto Scaling groups

DynamoDB auto scaling

AWS Lambda

DynamoDB global tables

AWS Lambda vs EC2: Comparison of AWS Compute Resources - Simform

Managing throughput capacity automatically with DynamoDB auto scaling - Amazon DynamoDB

AWS Aurora Global Database vs. DynamoDB Global Tables

Amazon Simple Queue Service (SQS)

https://docs.aws.amazon.com/vpc/latest/privatelink/vpc-endpoints-access.html

https://aws.amazon.com/premiumsupport/knowledge-center/vpc-reduce-nat-gateway-transfer-costs/

VPC endpoint policies enable you to control access by either attaching a policy to a VPC endpoint or by using additional fields in a policy that is attached to an IAM user, group, or role to restrict access to only occur via the specified VPC endpoint

The core issue is high latency when serving images during traffic spikes. The current design resizes images dynamically and caches them locally inside ECS containers. With AWS Fargate, containers are ephemeral and scale in and out based on load. Local container caches are not shared across tasks, so cache hit rates drop during scaling events, forcing repeated image resizing. This increases CPU usage, startup latency, and response times under load.

The lowest operational overhead and most effective solution is to offload image delivery entirely from the application layer and use edge caching. Amazon CloudFront is designed to cache static content at edge locations close to end users, dramatically reducing latency and backend load. Amazon S3 is a durable, highly scalable object store that is well suited for serving static assets such as images.

Option A moves image delivery to a CloudFront + S3 architecture. By pre-scaling images and storing them in S3, the application no longer performs on-demand image resizing during requests. CloudFront caches the images at edge locations, so subsequent requests are served directly from the edge with minimal latency. The ALB remains the origin for dynamic content, while image requests are routed to the S3 origin using cache behaviors. This approach is fully managed, highly scalable, and requires minimal changes to the application logic once images are pre-generated.

Option B introduces ElastiCache, which adds operational overhead and complexity. The application must manage cache keys, eviction, and failure scenarios. ElastiCache is better suited for low-latency data access patterns rather than large static objects like images, and it does not provide global edge caching.

Option C adds unnecessary complexity by introducing an Aurora database as part of the caching layer. Databases are not designed to manage cache metadata for static assets at scale, and this design increases operational overhead without improving latency compared to CloudFront.

Option D is not appropriate because API Gateway caching is intended for API responses, not for efficient delivery of large static binary objects such as images. Replacing the ALB with API Gateway also introduces request size, payload, and cost considerations and does not provide global edge caching comparable to CloudFront for image delivery.

Therefore, using Amazon CloudFront with Amazon S3 for pre-scaled images provides the lowest latency, highest scalability, and least operational overhead.

This option allows the company to use AWS Client VPN to enable secure and private access to the Amazon ES cluster from any location1. By configuring and setting up an AWS Client VPN endpoint, the company can create a secure tunnel between the developers’ devices and the VPC2. By associating the Client VPN endpoint with a subnet in the VPC, the company can ensure that the trafficfrom the developers’ devices is routed to the Amazon ES cluster within the VPC3. By configuring a Client VPN self-service portal, the company can enable the developers to download and install the client for Client VPN, which is based on OpenVPN4. By instructing the developers to connect by using the client for Client VPN, the company can allow them to access Amazon ES to analyze and visualize logs directly from their local development machines.

What is AWS Client VPN?

Creating a Client VPN endpoint

Associating a target network with a Client VPN endpoint

Configuring a self-service portal

The correct answer is A.

A. This solution meets the requirements because it allows the company to create different usage plans for each customer, with different request quotas and time periods. The usage plans can be associated with API keys, which can be distributed to the users of each customer. The API Gateway REST API can invoke the Lambda function using a proxy integration, which passes the request data to the function as input and returns the function output as the response.This solution is scalable, secure, and cost-effective12

B. This solution is incorrect because API Gateway HTTP APIs do not support usage plans or API keys.These features are only available for REST APIs3

C. This solution is incorrect because it does not provide a way to enforce request quotas for each customer. Lambda function aliases can be used to create different versions of the function, but they do not have any quota mechanism.Moreover, this solution exposes the Lambda function URLs directly to the customers, which is not secure or recommended4

D. This solution is incorrect because it does not provide a way to differentiate between customers or users. AWS WAF rate-based rules can be used to limit requests based on IP addresses, but they do not support any other criteria such as user agents or headers.Moreover, this solution adds unnecessary complexity and cost by using an ALB and a VPC56

https://docs.aws.amazon.com/IAM/latest/UserGuide/confused-deputy.html

This is the most secure way to allow org1 to access resources in org2 because it allows for least privilege security access. The customer should create an IAM role and assign the required permissions to the IAM role. The partner company should then use the IAM role’s Amazon Resource Name (ARN) and include the external ID in the IAM role’s trust policy when requesting access to perform the required tasks. This ensures that the partner company can only access the resources that it needs and only from the specific customer account.

A is correct because:

App2Containersupports packaging .NET Framework apps into containers without porting to .NET Core.

ECS with EC2gives full control over the OS and patching.

ALBhandles microservice-level load balancing.

RDS for SQL Serverwith Multi-AZ ensures high availability.

Options B, C, and D involve Aurora MySQL (incompatible with SQL Server features) orrequire .NET Core, which involves more significant application changes.

AWS Backup is a fully managed service that makes it easy to centralize and automate the creation, retention, and restoration of backups across AWS services. It provides a way to schedule automatic backups for CodeCommit repositories on an hourly basis. Additionally, it also supports cross-Region replication, which allows you to copy the backups to a second Region for disaster recovery.

By using AWS Backup, the company can set up an automatic and regular backup schedule for the CodeCommit repository, ensuring that the data is regularly backed up and stored in a second Region. This can provide a way to recover quickly from any disaster event that might occur.

For collecting data from remote sensors without internet connectivity, using an AWS Snowcone device with an Amazon EC2 instance running an FTP server presents a practical solution. This setup allows the sensors to upload data to the EC2 instance via FTP, and after the experiment, the Snowcone device can be returned to AWS for data ingestion into Amazon S3. This approach minimizes operational complexity and ensures efficient data transfer to AWS for further processing or storage.

AWS Documentation on AWS Snowcone and Amazon EC2 provides detailed guidance on deploying compute and storage capabilities in edge locations. This solutionleverages AWS ' s edge computing devices to address challenges associated with data collection in remote or disconnected environments.

D is correct because AWS Private CA supports resource sharing through AWS RAM, which allows you to share the CA across accounts in your AWS Organization securely. It ensures the CA private key remains secure and is never exported.

A is invalid because you cannot export a CA’s private key, and importing/exporting CAs this way is unsupported.

B is incorrect — IAM policies alone are not sufficient to share Private CAs across accounts.

C is not applicable because resource-based delegation policies do not apply to AWS Private CA.

https://aws.amazon.com/solutions/implementations/git-to-s3-using-webhooks/

https://medium.com/mindorks/building-webhook-is-easy-using-aws-lambda-and-api-gateway-56f5e5c3a596

https://aws.amazon.com/blogs/aws/new-attributes-based-access-control-with-aws-single-sign-on/

Comprehensive and Detailed in Depth Explanation:

A is correct because write throttling on DynamoDB means WCU (write capacity units) are insufficient. Increasing them will reduce the error rate.

D is correct because introducing Kinesis allows for efficient, high-throughput ingestion and batch processing, reducing the number of Lambda invocations and overall load.

This solution will give the Lambda function access to the internet by routing its outbound traffic through the NAT gateway, which has a public Elastic IP address. This will allow the external provider to whitelist the single public IP address associated with the NAT gateway, and enable the application to access the new service

Deploying a NAT gateway and associating an Elastic IP address with it, and then configuring the VPC to use the NAT gateway, will give the application the ability to access the new service. This is because the NAT gateway will be the single public IP address that the external provider needs for the allow list. The NAT gateway will allow the application to access the service, while keeping the underlying Lambda functions private.

When configuring NAT gateways, you should ensure that the route table associated with the NAT gateway has a route to the internet gateway with a target of the internet gateway. Additionally, youshould ensure that the security group associated with the NAT gateway allows outbound traffic from the Lambda functions.

The correct answer is D. Deploy the application on Amazon Elastic Kubernetes Service (Amazon EKS) with AWS Fargate and enable auto scaling behind an Application Load Balancer. Create additional read replicas for the DB instance. Create an Amazon Managed Streaming for Apache Kafka cluster and configure the application services to use the cluster. Store static content in Amazon S3 behind an Amazon CloudFront distribution.

Option D meets the requirements of the scenario because it allows you to reduce operational overhead and support the product release by using the following AWS services and features:

Amazon Elastic Kubernetes Service (Amazon EKS) is a fully managed service that allows you to run Kubernetes applications on AWS without needing to install, operate, or maintain your own Kubernetes control plane. You can use Amazon EKS to deploy your containerized application services on a Kubernetes cluster that is compatible with your existing tools and processes.

AWS Fargate is a serverless compute engine that eliminates the need to provision and manage servers for your containers. You can use AWS Fargate as the launch type for your Amazon EKS pods, which are the smallest deployable units of computing in Kubernetes. You can also enable auto scaling for your pods, which allows you to automatically adjust the number of pods based on the demand or custom metrics.

An Application Load Balancer (ALB) is a load balancer that distributes traffic across multiple targets in multiple Availability Zones using HTTP or HTTPS protocols. You can use an ALB to balance the load across your Amazon EKS pods and provide high availability and fault tolerance for your application.

Amazon RDS for PostgreSQL is a fully managed relational database service that supports the PostgreSQL open source database engine. You can create additional read replicas for your DB instance, which are copies of your primary DB instance that can handle read-only queries and improve performance. You can also useread replicas to scale out beyond the capacity of a single DB instance for read-heavy workloads.

Amazon Managed Streaming for Apache Kafka (Amazon MSK) is a fully managed service that makes it easy to build and run applications that use Apache Kafka to process streaming data. Apache Kafka is an open source platform for building real-time data pipelines and streaming applications. You can use Amazon MSK to create and manage a Kafka cluster that is highly available, secure, and compatible with your existing Kafka applications. You can also configure your application services to use the Amazon MSK cluster as a source or destination of streaming data.

Amazon S3 is an object storage service that offers high durability, availability, and scalability. You can store static content such as images, videos, or documents in Amazon S3 buckets, which are containers for objects. You can also serve static content directly from Amazon S3 using public URLs or presigned URLs.

Amazon CloudFront is a fast content delivery network (CDN) service that securely delivers data, videos, applications, and APIs to customers globally with low latency and high transfer speeds. You can use Amazon CloudFront to create a distribution that caches static content from your Amazon S3 bucket at edge locations closer to your users. This can improve the performance and user experience of your application.

Option A is incorrect because creating an EC2 Auto Scaling group behind an ALB would not reduce operational overhead as much as using AWS Fargate with Amazon EKS, as you would still need to manage EC2 instances for your containers. Creating additional read replicas for the DB instance would not provide high availability or fault tolerance in case of a failure of the primary DB instance, unlike deploying the DB instance in Multi-AZ mode. Creating Amazon Kinesis data streams would not be compatible with your existing Apache Kafka applications, unlike using Amazon MSK.

Option B is incorrect because creating an EC2 Auto Scaling group behind an ALB would not reduce operational overhead as much as using AWS Fargate with Amazon EKS, as you would still need to manage EC2 instances for your containers. Creating Amazon Kinesis data streams would not be compatible with your existing Apache Kafka applications, unlike using Amazon MSK. Storing and serving static content directly from Amazon S3 would not provide optimal performance and user experience, unlike using Amazon CloudFront.

Option C is incorrect because deploying the application on a Kubernetes cluster created on the EC2 instances behind an ALB would not reduce operational overhead as much as using AWS Fargate with Amazon EKS, as you would still need to manage EC2 instances and Kubernetes control plane for your containers. Using Amazon API Gateway to interact with the application would add an unnecessary layer of complexity and cost to your architecture, as you would need to create and maintain an API gateway that proxies requests to your ALB.

This explanation is based on AWS documentation and best practices but is paraphrased, not a literal extract.

The company wants to move from a manual EC2 and EBS-based workflow to a containerized application on Amazon EKS and automate data movement. The solution must:

Support automated transfer of raw and processed data.

Offer multiprotocol support.

Be directly usable from the EKS cluster as a mounted volume.

Minimize operational effort by using managed services where possible.

AWS DataSync is a managed service designed to move data between on-premises storage and AWS storage services or between AWS storage services. It can perform scheduled or continuous transfers with minimal operational overhead. For storage accessible from Amazon EKS, a shared file system that supports mounting as a volume is appropriate.

Amazon FSx for NetApp ONTAP provides a fully managed file system with multiprotocol support, including NFS and SMB, and supports features such as snapshots and storage efficiencies. Because it supports multiple protocols, it satisfies the requirement for multiprotocol access and can be mounted by applications running in Amazon EKS using standard Kubernetes persistent volume mechanisms.

In the correct solution (option C), DataSync is used to copy raw data from the on-premises environment to FSx for NetApp ONTAP. The FSx for NetApp ONTAP file system is then mounted as a volume in the EKS cluster, allowing the containerized analytics processing logic to read and write data directly. After processing, DataSync is again used to copy processed data from FSx for NetApp ONTAP to Amazon S3 for long-term storage. This leverages DataSync’s native integration with both FSx for NetApp ONTAP and Amazon S3, and avoids the need to run or manage custom upload tooling.

Option A uses Amazon EFS, which supports NFS but does not provide multiprotocol support (for example, SMB), so it does not fully meet the multiprotocol requirement. It also introduces AWS Transfer for SFTP for the processed data upload, which adds an additional managed endpoint and SFTP-based flow, increasing complexity relative to using DataSync end-to-end.

Option B uses Amazon FSx for Lustre, which is optimized for high-performance compute workloads and integrates well with S3, but it is not a multiprotocol file system and is typically accessed via NFS. It does not meet the stated multiprotocol requirement.

Option D uses FSx for NetApp ONTAP (which supports multiprotocol) but relies on AWS Transfer for SFTP to move processed data to S3. While this can work, it adds another managed input endpoint and requires SFTP client configuration and management. Using DataSync directly from FSx for NetApp ONTAP to Amazon S3 (as in option C) is more straightforward, better suited for automated large-scale transfers, and involves less operational overhead.

Therefore, option C meets all the requirements with the least operational effort by using DataSync with FSx for NetApp ONTAP and S3.

The company should deploy a new Amazon Elastic File System (Amazon EFS) Multi-AZ file system. The company should configure the file system for 75 MiBps of provisioned throughput. The company should implement replication to a file system in the DR Region. This solution will meet the requirements because Amazon EFS is a serverless, fully elastic file storage service that lets you share file data without provisioning or managing storage capacity and performance. Amazon EFS is built to scale on demand to petabytes without disrupting applications, growing and shrinking automatically as you add and remove files1. By deploying a new Amazon EFS Multi-AZ file system, the company can create a single location for updates to application data for all instances. A Multi-AZ file system replicates data across multiple Availability Zones (AZs) within a Region, providing high availability and durability2. By configuring the file system for 75 MiBps of provisioned throughput, the company can ensure that it meets the peak operations requirement of 225 MiBps of read throughput. Provisioned throughput is a feature that enables you to specify a level of throughput that the file system can drive independent of the file system’s size or burst credit balance3. By implementing replication to a file system in the DR Region, the company can make a copy of the data available in another AWS Region for disaster recovery. Replication is a feature that enables you to replicate data from one EFS file system to another EFS file system across AWS Regions. The replication process has an RPO of less than 1 hour.

The other options are not correct because:

Deploying a new Amazon FSx for Lustre file system would not provide a single location for updates to application data for all instances. Amazon FSx for Lustre is a fully managed service that provides cost-effective, high-performance storage for compute workloads. However, it does not support concurrent write access from multiple instances. Using AWS Backup to back up the file system to the DR Region would not provide real-time replication of data. AWS Backup is a service that enables you to centralize and automate data protection across AWS services. However, it does not support continuous data replication or cross-Region disaster recovery.

Deploying a General Purpose SSD (gp3) Amazon Elastic Block Store (Amazon EBS) volume with 225 MiBps of throughput would not provide a single location for updates to application data for all instances. Amazon EBS is a service that provides persistent block storage volumes for use with Amazon EC2 instances. However, it does not support concurrent access from multiple instances, unless Multi-Attach is enabled. Enabling Multi-Attach for the EBS volume would not provide Multi-AZ resilience or cross-Region replication. Multi-Attach is a feature that enables you to attach an EBS volume to multiple EC2 instances within the same Availability Zone. Using AWS Elastic Disaster Recovery to replicate the EBS volume to the DR Region would not provide real-time replication of data. AWS Elastic Disaster Recovery (AWS DRS) is a service that enables you to orchestrate and automate disaster recovery workflows across AWS Regions. However, it does not support continuous data replication or sub-hour RPOs.

Deploying an Amazon FSx for OpenZFS file system in both the production Region and the DR Region would not be as simple or cost-effective as using Amazon EFS. Amazon FSx for OpenZFS is a fully managed service that provides high-performance storage with strong data consistency and advanced data management features for Linux workloads. However, it requires more configuration and management than Amazon EFS, which is serverless and fully elastic. Creating an AWS DataSync scheduled task to replicate the data from the production file system to the DR file system every 10 minutes would not provide real-time replication of data. AWS DataSync is a service that enables you to transfer data between on-premises storage and AWS services, or between AWS services. However, it does not support continuous data replication or sub-minute RPOs.

https://docs.aws.amazon.com/organizations/latest/userguide/orgs_manage_accounts_access.html#orgs_manage_accounts_access-cross-account-role " When you create a member account using the AWS Organizations console, AWS Organizations automatically creates an IAM role named OrganizationAccountAccessRole in the account " you need OrganizationAccountAccessRole in member account to create an read-only role and use role from security team to assume this read-only role.

Amazon EC2 Spot Instances offer spare compute capacity at steep discounts compared to On-Demand prices. Spot Instances can be interrupted by EC2 with two minutes of notification when EC2 needs the capacity back. Amazon EMR can handle Spot interruptions gracefully by decommissioning the nodes and redistributing the tasks to other nodes. By launching all nodes on Spot Instances in an instance fleet, the solutions architect can minimize the compute costs of the EMR cluster. An instance fleet is a collection of EC2 instances with different types and sizes that EMR automatically provisions to meet a defined target capacity. By terminating the cluster when the processing is completed, the solutions architect can avoid paying for idle resources. References:

https://docs.aws.amazon.com/emr/latest/ManagementGuide/emr-managed-scaling.html

https://docs.aws.amazon.com/emr/latest/ManagementGuide/emr-instance-fleet.html

https://aws.amazon.com/blogs/big-data/optimizing-amazon-emr-for-resilience-and-cost-with-capacity-optimized-spot-instances/

Moving the application frontend to a static website that is hosted on Amazon S3 will save cost as S3 is cheaper than running EC2 instances.

Using Spot instances for the backend EC2 instances will also save cost, as they are significantly cheaper than On-Demand instances. This will be suitable for the application, as it has minimal traffic during the rest of the day, and the availability of spot instances will not negatively affect the application ' s availability.

With AWS PrivateLink, the marketing team can create an endpoint service to share theirinternal application with other accounts securely using private IP addresses. They can grant permission to specific AWS accounts to connect to the service and create interface VPC endpoints in the other accounts to access the application by using private IP addresses. This option does not require any changes to the network of the other business units, and it does not require peering or NATing. This solution is both scalable and secure.

https://aws.amazon.com/blogs/networking-and-content-delivery/connecting-networks-with-overlapping-ip-ranges/

https://aws.amazon.com/blogs/compute/implementing-canary-deployments-of-aws-lambda-functions-with-alias-traffic-shifting/

https://docs.aws.amazon.com/lambda/latest/dg/configuration-aliases.html

The company should create an Amazon CloudFront distribution with the ALB as the origin. The company should add a custom header and random value on the CloudFront domain. The company should configure the ALB to conditionally forward traffic if the header and value match. The company should also deploy an AWS WAF web ACL that includes an appropriate rule group. The company should associate the web ACL with the Amazon CloudFront distribution. This solution will meet the requirements most cost-effectively because Amazon CloudFront is a fast content delivery network (CDN) service that securely deliversdata, videos, applications, and APIs to customers globally with lowlatency, hightransfer speeds, all within a developer-friendly environment1. By creating an Amazon CloudFront distribution with the ALB as the origin, the company can improve the performance andavailability of its application by caching static content at edge locations closer to end users. By adding a custom header and random value on the CloudFront domain, the company can prevent direct access to the ALB and ensure that only requests from CloudFront are forwarded to the ECS tasks. By configuring the ALB to conditionally forward traffic if the header and value match, the company can implement origin access identity (OAI) for its ALB origin. OAI is a feature that enables you to restrict access to your content by requiring users to access your content through CloudFront URLs2. By deploying an AWS WAF web ACL that includes an appropriate rule group, the company can prevent attacks and ensure business continuity with minimal service interruptions during an ongoing attack. AWS WAF is a web application firewall that lets you monitor and control web requests that are forwarded to your web applications. You can use AWS WAF to define customizable web security rules that control which traffic can access your web applications and which traffic should be blocked3. By associating the web ACL with the Amazon CloudFront distribution, the company can apply the web security rules to all requests that are forwarded by CloudFront.

The other options are not correct because:

Deploying the application in two AWS Regions and configuring Amazon Route 53 to route to both Regions with equal weight would not prevent attacks or ensure business continuity. Amazon Route 53 is a highly available and scalable cloud Domain Name System (DNS) web service that routes end users to Internet applications by translating names like www.example.com into numeric IP addresses4. However, routing traffic to multiple Regions would not protect against attacks or provide failover in case of an outage. It would also increase operational complexity and costs compared to using CloudFront and AWS WAF.

Configuring auto scaling for Amazon ECS tasks and creating a DynamoDB Accelerator (DAX) cluster would not prevent attacks or ensure business continuity. Auto scaling is a feature that enables you to automatically adjust your ECS tasks based on demand or a schedule. DynamoDB Accelerator (DAX) is a fully managed, highly available, in-memory cache for DynamoDB that delivers up to a 10x performance improvement. However, these features would not protect against attacks or provide failover in case of an outage. They would also increase operational complexity and costs compared to using CloudFront and AWS WAF.

Configuring Amazon ElastiCache to reduce overhead on DynamoDB would not prevent attacks or ensure business continuity. Amazon ElastiCache is a fully managed in-memory data store service that makes it easy to deploy, operate, and scale popular open-source compatible in-memory data stores. However, this service would not protect against attacks or provide failover in case of an outage. It would also increase operational complexity and costs compared to using CloudFront and AWS WAF.

Creating a headless Aurora DB cluster in the secondary Region as part of an Aurora global database ensures continuous, low-latency replication without running active instances in the secondary Region.

This configuration meets the RTO and RPO requirements by allowing rapid promotion of the secondary cluster in a failover scenario.

It also reduces operational costs compared to continuously running standby instances in the secondary Region.

This aligns with AWS best practices for DR and cross-Region resiliency.