Explanation: Amazon Aurora (with PostgreSQL compatibility) and Amazon EC2 can both host PostgreSQL databases. Aurora is a managed database service that provides a fully compatible PostgreSQL environment with automated management. EC2 can also host PostgreSQL, but it requires more manual setup and maintenance. Amazon S3 and EFS do not host databases, and Amazon OpenSearch Service is intended for search and analytics, not relational databases.

Explanation: AWS SDKs are a set of tools that allow users to connect with AWS and deploy resources programmatically. AWS SDKs provide libraries, code samples, documentation, and other resources to help users write code that interacts with AWS APIs. AWS SDKs support various programming languages, such as Java, Python, Ruby, .NET, Node.js, Go, and more. AWS SDKs make it easier for users to access AWS services, such as Amazon S3, Amazon EC2, Amazon DynamoDB, AWS Lambda, and more, from their applications. AWS SDKs also handle tasks such as authentication, error handling, retries, and data serialization, so users can focus on their application logic . The other options are not AWS services or tools that give users the ability to connect with AWS and deploy resources programmatically. Amazon QuickSight is a business intelligence service that lets users create and share interactive dashboards and visualizations1. AWS PrivateLink is a service that enables users to securely access services hosted on AWS in a scalable and cost-effective manner2. AWS Direct Connect is a service that establishes a dedicated network connection between a user’s premises and AWS3.

Explanation: Amazon QuickSight is an AWS service that provides business intelligence and data visualization capabilities. Amazon QuickSight enables you to ingest, analyze, and display data from various sources, such as AWS Cost and Usage Reports, Amazon S3, Amazon Athena, Amazon Redshift, and Amazon RDS. You can use Amazon QuickSight to create interactive dashboards and charts that show insights and trends from your data. You can also share your dashboards and charts with other users or embed them into your applications.

Explanation: Refactoring involves re-architecting and modifying an application to take advantage of cloud-native features. In this case, the company wants to modernize a monolithic application by breaking it into microservices. This process aligns with the Refactor strategy, which is aimed at modernizing and re-architecting applications. Rehost, Repurchase, and Replatform do not involve the level of re-architecting needed to move from a monolithic to a microservices architecture.

Explanation: AWS Outposts is a fully managed service that extends AWS infrastructure, services, APIs, and tools to customer premises. By providing local access to AWS managed infrastructure, AWS Outposts enables customers to build and run applications on premises using the same programming interfaces as in AWS Regions, while using local compute and storage resources for lower latency and local data processing needs. An Outpost is a pool of AWS compute and storage capacity deployed at a customer site. AWS operates, monitors, and manages this capacity as part of an AWS Region. You can create subnets on your Outpost and specify them when you create AWS resources such as EC2 instances, EBS volumes, ECS clusters, and RDS instances. Instances in Outpost subnets communicate with other instances in the AWS Region using private IP addresses, all within the same VPC. Outposts solutions allow you to extend and run native AWS services on premises, and is available in a variety of form factors, from 1U and 2U Outposts servers to 42U Outposts racks, and multiple rack deployments. With AWS Outposts, you can run some AWS services locally and connect to a broad range of services available in the local AWS Region2. AWS Outposts is a hybrid cloud deployment model that uses AWS Outposts as part of the application deployment infrastructure. Hybrid cloud is a cloud computing environment that uses a mix of on-premises, private cloud, and public cloud services with orchestration between the platforms. Hybrid cloud provides businesses with greater flexibility, more deployment options, and optimized costs. By using AWS Outposts, customers can benefit from the fully managed infrastructure, services, APIs, and tools of AWS on premises, while still having access to the full range of AWS services available in the Region for a truly consistent hybrid experience3.

Explanation: AWS Application Discovery Service helps companies gather information about on-premises data centers to support migration planning. It collects data on system configuration, resource utilization, and network dependencies, providing essential insights for migration. AWS DataSync and Storage Gateway are used for data transfer, while AWS DMS is for database migration specifically.

Explanation: Compute Savings Plans provide the most flexibility and help to reduce your costs by up to 66%. These plans automatically apply to EC2 instance usage regardless of instance family, size, AZ, Region, OS or tenancy, and also apply to Fargate or Lambda usage. For example, with Compute Savings Plans, you can change from C4 to M5 instances, shift a workload from EU (Ireland) to EU (London), or move a workload from EC2 to Fargate or Lambda at any time and automatically continue to pay the Savings Plans price.

Explanation: AWS Elastic Beanstalk, Amazon Aurora, and AWS Auto Scaling are managed services that reduce the operational overhead for the customers. AWS is responsible for security patching, backups, and termination of these services. However, the customers are still responsible for configuring IAM access controls to manage the permissions and policies for their AWS resources. This is part of the AWS shared responsibility model, which defines the security and compliance responsibilities of AWS and the customers. You can learn more about the AWS shared responsibility model from this whitepaper or this digital course.

Explanation: AWS serverless computing is a way of building and running applications without thinking about servers. AWS manages the infrastructure for you, so you don’t have to provision, scale, patch, or monitor servers. You only pay for the compute time you consume, and you can focus on your application logic instead of managing servers12.

Explanation: AWS Cost Explorer is the AWS service or tool that helps users visualize, understand, and manage spending and usage over time. AWS Cost Explorer is a webbased interface that allows users to access interactive graphs and tables that display their AWS costs and usage data. Users can create custom reports that analyze cost and usage data by various dimensions, such as service, region, account, tag, and more. Users can also view historical data for up to the last 12 months, forecast future costs for up to the next 12 months, and get recommendations for cost optimization. AWS Cost Explorer also provides preconfigured views that show common cost and usage scenarios, such as monthly spend by service, daily spend by linked account, and Reserved Instance utilization. Users can use AWS Cost Explorer to monitor their AWS spending and usage trends, identify cost drivers and anomalies, and optimize their resource allocation and budget planning.

Explanation: Using EC2 instances in multiple Availability Zones is an AWS infrastructure solution that meets the requirements of migrating a high performance computing (HPC) application to AWS with fault tolerance and failover capabilities, and with the least latency between components. An Availability Zone is a physically isolated location within an AWS Region that has its own power, cooling, and network connectivity. EC2 instances within the same Region can communicate with each other using low-latency private IP addresses. By using EC2 instances in multiple Availability Zones, the company can achieve fault tolerance and failover for their HPC application, because they can distribute the workload and data across different locations that are independent of each other. If one Availability Zone becomes unavailable or impaired, the company can redirect the traffic and data to another Availability Zone without affecting the performance and availability of the application5.

Explanation: Amazon ElastiCache is a fully managed in-memory data store and cache service that delivers sub-millisecond response times to applications. You can use ElastiCache as a primary data store for your applications, or as a cache to improve the performance of your existing databases. ElastiCache supports two popular open-source inmemory engines: Redis and Memcached5.