SAA-C03 Exam Dumps - AWS Certified Solutions Architect - Associate (SAA-C03)

Amazon S3 Bucket Keys reduce the cost of AWS KMS API requests by generating a data key at the bucket level instead of individually calling KMS for every object read or written. This approach is particularly effective when workloads, such as ML pipelines, involve reading large numbers of encrypted objects. Switching to AWS managed keys (A) does not reduce the frequency of API calls. Removing encryption (B) would violate compliance/security requirements. Using CloudHSM (C) adds cost and operational burden. Therefore, the correct solution is D — enabling S3 Bucket Keys with SSE-KMS, which significantly reduces decryption costs while maintaining secure encryption.

To build a distributed, serverless, event-driven workflow with minimal operational overhead, AWS Step Functions orchestrating AWS Lambda is the best fit. Step Functions provides a managed state machine service that coordinates multiple steps, handles retries and error handling patterns, and maintains execution state without requiring the company to run orchestration servers. Lambda provides serverless compute for each workflow task, scaling automatically with demand and eliminating server management.

Option D directly matches “performing different aspects of the workflow” because Step Functions is specifically designed to model multi-step business processes and coordinate activities across services. It also aligns with “minimize operational overhead” because both Step Functions and Lambda are managed services: there are no instances to patch, no cluster management, and scaling is handled by the platform.

Option B contradicts the serverless goal by deploying the application on EC2 instances, increasing operational overhead (capacity management, patching, scaling, and availability concerns). Option C mixes eventing with scheduling: EventBridge can route events, but invoking Lambda “on a schedule” is not the same as orchestrating a multi-step workflow with branching, waiting, retries, compensation, and state tracking. EventBridge is excellent as an event bus, but Step Functions is the purpose-built workflow orchestrator. Option A is a mismatch because AWS Glue is primarily an ETL/data integration service; while it can run jobs and triggers, it is not the general workflow orchestrator for arbitrary application steps, and using it to invoke Lambda for a broad workflow is less direct and typically less operationally clean than a Step Functions state machine.

Therefore, D is the most aligned solution for serverless, distributed workflow orchestration with low operational burden.

A mix of On-Demand Instances and Spot Instances is the best cost-optimized option when the company wants lower cost but does not want long-term commitments. On-Demand Instances provide baseline reliability and require no upfront payment or term commitment. Spot Instances can significantly reduce compute cost for flexible portions of the Auto Scaling group, as long as the application can tolerate replacement capacity when Spot capacity is interrupted. Reserved Instances require a commitment, so options B and D violate the requirement. Dedicated Instances are generally used for compliance or isolation requirements and do not optimize cost for a scalable web application. Auto Scaling groups can use multiple purchasing options to balance availability and cost.

Spot Instances are the best pricing model because the jobscan tolerate interruptions, and the company wants the most cost-effective option. AWS recommends theprice-capacity-optimizedstrategy for Spot because it selects pools that balancelow pricewithlower interruption risk. Using multiple instance types in the Auto Scaling group also helps the company stay flexible enough to adopt newer generations over time. Reserved Instances do not fit as well because they reduce flexibility and do not align with the requirement to keep shifting toward the latest instance generations each year. Capacity-optimized alone minimizes interruption risk, but AWS recommends price-capacity-optimized when you want both lower interruption rates and better prices. Therefore, Spot with price-capacity-optimized allocation is the strongest answer.

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EBS Encryption:

Default EBS Encryption: Can be enabled for new EBS volumes.

Use of AWS KMS: Specify AWS KMS keys to handle encryption and decryption of data transparently.

Amazon RDS Encryption:

RDS Encryption: Encrypts the underlying storage for RDS instances using AWS KMS.

Configuration: Enable encryption when creating the RDS instance or modify an existing instance to enable encryption.

Least Amount of Changes:

Both EBS and RDS support seamless encryption with AWS KMS, requiring minimal changes to the existing infrastructure.

Enables compliance with regulatory requirements without modifying the application.

Operational Efficiency: Using AWS KMS for both EBS and RDS ensures a consistent, managed approach to encryption, simplifying key management and enhancing security.

To protect against a Regional failure, the application must be deployed in multiple Regions. Amazon Route 53 DNS failover with health checks allows traffic to be automatically routed to a healthy Region when the primary becomes unavailable, meeting high availability and disaster recovery requirements.

A read replica is the best answer because the new application needs to read frequently changing data while minimizing load on the production writer. Amazon RDS read replicas are designed to offload read traffic from the primary DB instance, which improves overall performance for the main workload. ElastiCache is not the best fit because the application rarely repeats the same query, so a cache would not provide strong benefit. An ALB is unrelated to database querying, and snapshots are not appropriate for querying near-current data. Since the requirement is fresh read access with minimal impact on the primary database, using a read replica is the correct architectural choice.

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To optimize costs for both Amazon EC2 and AWS Fargate, the best option is a Compute Savings Plan because it offers flexibility across instance families, Regions, and compute options including EC2, AWS Fargate, and AWS Lambda.

Unlike EC2 Instance Savings Plans, which apply only to specific instance families, Compute Savings Plans apply across multiple services.

Since the company does not want to commit to multi-year contracts or large upfront payments, the 1-year No Upfront Compute Savings Plan provides the greatest flexibility with no upfront capital commitment, while still offering cost savings over On-Demand pricing.

This option also aligns with cost-optimization best practices by allowing for scalability and service mix flexibility.

🔗 Reference:

AWS Compute Savings Plans

AWS Pricing Models