Design Resilient Architectures

A retail company runs three microservices (product catalog, shopping cart, and user profile) as separate Amazon ECS services behind a single public entry point. The team wants customers to reach each microservice through the same domain name, with requests routed to the correct service based on the URL path (for example, /catalog, /cart, and /profile). The solution must scale automatically and require minimal operational overhead. Which approach BEST meets these requirements?

A gaming company runs a real-time multiplayer backend on Amazon ECS. The workload communicates over raw TCP, requires the ability to handle millions of requests per second with ultra-low latency, and the company's enterprise customers require a set of static IP addresses to allowlist in their firewalls. Which load balancing solution best meets these requirements?

A company runs a serverless REST API using Amazon API Gateway backed by AWS Lambda functions that write to a small Amazon RDS for PostgreSQL Multi-AZ instance. During marketing campaigns, sudden traffic spikes cause thousands of concurrent Lambda invocations to open connections to the database simultaneously, exhausting the connection limit and causing widespread request failures. The team wants to smooth out these bursts so the database is never overwhelmed, while ensuring no write requests are lost. Which solution best meets these requirements?

A company exposes a public REST API through Amazon API Gateway to several partner organizations. Each partner has purchased a different subscription tier, and the company must enforce a distinct monthly request quota and per-second rate limit for each partner while identifying which partner made each call. The solution should require minimal custom code. What should the solutions architect implement?

A company runs a stateless web application on EC2 instances behind an Application Load Balancer. All instances currently launch in a single Availability Zone within one Region. During a recent AZ outage, the entire application became unavailable for several hours. The team wants to improve fault tolerance so the application survives the loss of a single Availability Zone with no manual intervention, while keeping costs reasonable. Which change should the solutions architect make?

A media company runs a stateless web application on Amazon EC2 instances behind an Application Load Balancer in an Auto Scaling group. Traffic is unpredictable, with sudden spikes during breaking news events. The operations team currently manages capacity manually and often over-provisions to be safe, wasting money during quiet periods. They want the group to automatically maintain healthy performance while minimizing cost, using the simplest configuration to manage. Which scaling approach best meets these requirements?

A financial services company runs its primary transactional workload on an Amazon Aurora MySQL cluster in the us-east-1 Region. Regulatory requirements dictate that the application must be able to recover in a second Region with an RPO of less than 1 second and an RTO of under 5 minutes in the event of a full Region outage. The solution must minimize replication lag and avoid impacting the performance of the primary cluster. Which approach best meets these requirements?

A financial reporting application runs on Amazon Aurora MySQL. During business hours, analysts generate large numbers of read-only dashboard queries that overwhelm the primary database instance, causing write transactions from the core application to slow down. The team wants to offload the reporting queries and improve availability without changing the application's write path. Which solution best meets these requirements?

A company runs a stateless web application on an Amazon EC2 Auto Scaling group behind an Application Load Balancer (ALB) across three Availability Zones. Occasionally, an instance's application process hangs and returns HTTP 500 errors, but the EC2 instance itself continues running and passes the default EC2 status checks. The Auto Scaling group therefore does not replace these unhealthy instances, and users intermittently receive errors. What should the solutions architect do to ensure unhealthy instances are automatically replaced?

A company runs an internal reporting application on EC2 instances backed by an Amazon RDS for PostgreSQL database in the us-east-1 Region. Management wants a disaster recovery plan for a full Regional outage but has stated the application is non-critical: a recovery time of up to 24 hours and data loss of up to a few hours are acceptable. The primary goal is to keep ongoing DR costs as low as possible. Which disaster recovery strategy best meets these requirements?

A media company hosts a popular news website on a fleet of EC2 instances behind an Application Load Balancer in a single Region. During breaking-news events, traffic spikes cause the instances to become overloaded serving repeated requests for the same static images, CSS, and JavaScript files, degrading page load times for global users. The team wants to reduce load on the origin and improve latency for visitors worldwide with minimal application changes. Which solution best meets these requirements?

A media company hosts an educational video platform on an Application Load Balancer backed by an Auto Scaling group of EC2 instances in the us-east-1 Region. Users worldwide report slow initial load times and buffering, especially in Asia and Europe. The videos are large static MP4 files stored on the instances, and the origin is being overwhelmed by repeated downloads of the same files. Which solution BEST improves global performance while reducing load on the origin?

A gaming company runs a leaderboard service backed by an Amazon DynamoDB table. During tournaments, the same set of player records is read millions of times per minute, causing high read capacity consumption and occasional throttling. Read latency has climbed into the low milliseconds, but the application requires microsecond-level response times for repeated reads. Writes remain relatively infrequent. Which solution best meets these requirements with the least application change?

A gaming company runs a serverless leaderboard application backed by an Amazon DynamoDB table in us-east-1. The player base is expanding rapidly in Europe and Asia, and users in those regions report high read and write latency. The company also wants the application to remain fully operational for writes if an entire AWS Region becomes unavailable. Which solution best meets these requirements with the least operational overhead?

A development team is deploying a new containerized microservice. They want to run Docker containers using Kubernetes-compatible tooling because their existing on-premises workloads use Kubernetes manifests, but they do not want to manage, patch, or scale the underlying EC2 worker nodes. Which AWS service combination best meets these requirements with the least operational overhead?

A company runs a stateless containerized order-processing microservice on an Amazon ECS cluster backed by EC2 instances. The operations team spends significant time patching the underlying EC2 hosts, managing the cluster's capacity, and right-sizing instances as traffic fluctuates throughout the day. Leadership wants to eliminate the burden of managing the underlying compute infrastructure while keeping the workload containerized and able to scale automatically with demand. Which approach best meets these requirements?

A media company runs a batch image-processing service on Amazon ECS with AWS Fargate. Jobs arrive in an Amazon SQS queue, and worker tasks pull messages to process them. During the day, queue depth is minimal, but overnight batch uploads cause tens of thousands of messages to accumulate, and tasks fall far behind. The team wants the number of Fargate tasks to automatically match the backlog so jobs complete faster during spikes, while scaling in to reduce cost when the queue empties. Which approach best meets these requirements?

A company runs a web application as a set of containers on Amazon ECS with the Fargate launch type behind an Application Load Balancer. The application stores user session data in the local memory of each container. During scale-in events triggered by an Auto Scaling policy, users are frequently logged out and lose their shopping cart contents. The team wants to make the containers fully stateless so they can be scaled in and out or replaced without affecting user sessions. Which approach best meets this requirement?

A company runs a content management system (CMS) on a fleet of EC2 instances behind an Application Load Balancer, spread across three Availability Zones in an Auto Scaling group. All instances must read and write to a common set of uploaded media files and user documents with a POSIX file system interface. The current design stores these files on an EBS volume attached to a single instance, which has become a single point of failure and cannot be shared. Which storage solution best provides shared, highly available access for the entire fleet with the least operational overhead?

A financial services company runs a session-based web application backed by an Amazon ElastiCache for Redis cluster that stores user session data. During a recent Availability Zone disruption, the primary node became unavailable and the application experienced several minutes of downtime while the team manually rebuilt the cache. The company needs the caching layer to recover automatically with minimal downtime if a node fails. Which configuration change best meets this requirement?