Amazon Web Services DVA-C02 Exam With Confidence Using Practice Dumps

Amazon API Gateway is a service that enables developers to create, publish, maintain, monitor, and secure APIs at any scale. The developer can define a development stage on the API Gateway API and instruct the other developers to point the endpoints to the development stage. This way, the developer can provide beta access to the new version of the API without affecting customers who use the production stage. This solution will meet the requirements with the least operational overhead.

This is a cross-account access pattern using STS AssumeRole. Account A owns the DynamoDB table and has created an IAM role (AccessPII) with permissions to access the table. Account A also configured a trust policy that allows principals from Account B to assume the role. That trust policy alone is not enough; the caller in Account B must also be allowed to call sts:AssumeRole.

Therefore, in Account B, the EC2 instance profile role (the role attached to the EC2 instances running the app) must have permission to assume the role in Account A. That is Option A.

Next, the application must actually obtain temporary credentials for the Account A role. The standard way is to call STS AssumeRole in the application logic (or use an SDK credential provider that assumes a role). This yields temporary credentials that have the permissions of the AccessPII role, allowing DynamoDB access in Account A. That is Option D.

Option B is not correct because granting direct DynamoDB table permissions in Account B does not grant access to a table owned by Account A unless Account A also grants access via a resource policy (DynamoDB resource policies exist but the scenario already sets up role assumption; the intended solution is AssumeRole).

Option C is incomplete/wrong: getting temporary credentials from the EC2 role alone gives permissions of the EC2 role in Account B, not the permissions in Account A. You must assume the cross-account role.

Option E is for IAM user MFA session tokens, not cross-account role assumption for an EC2 role.

Therefore, grant sts:AssumeRole to the EC2 role and call AssumeRole in code.

The workload is a classic “hot key / hot dataset” pattern: many reads repeatedly target a small subset of items. The best way to improve performance and reduce latency is to add a caching layer so the application does not hit DynamoDB for every read.

Option B is purpose-built for DynamoDB read acceleration: DynamoDB Accelerator (DAX) is an in-memory cache that sits in front of DynamoDB and is API-compatible for many DynamoDB operations. DAX can dramatically reduce read latency (often to microseconds) for frequently accessed items and offload read traffic from the table.

Option A can also help: ElastiCache (Redis/Memcached) can be used as an application-managed cache. This is useful when the application wants more control over caching strategy, TTLs, and non-DynamoDB data caching. For ECS applications, ElastiCache is a common high-performance caching choice.

Why not the others:

C (strongly consistent reads) typically increases latency and capacity consumption; it does not improve performance for repeated reads.

D (increase read capacity) can reduce throttling, but it does not reduce latency as effectively as caching and can be more expensive for hot-read patterns.

E (adaptive capacity) helps DynamoDB handle uneven workloads, but it is not a direct performance boost like caching for repeated reads of a small dataset.

Therefore, adding caching via ElastiCache and/or DAX best improves performance. With “select two,” A and B are correct.