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

Amazon S3 event notifications can invoke AWS Lambda functions at very high rates during traffic spikes. In this scenario, up to 500 objects per minute can result in hundreds of concurrent Lambda invocations. By default, Lambda functions share the account’s unreserved concurrency pool , which can cause throttling if the pool is exhausted by sudden bursts.

AWS Lambda reserved concurrency guarantees a specific number of concurrent executions for a function. By configuring reserved concurrency, the developer ensures that sufficient execution capacity is always available for this specific function, regardless of other Lambda workloads in the account. This prevents throttling during high-volume S3 event bursts.

Increasing the timeout (Option A) does not address concurrency limits. Adding a layer (Option B) does not solve invocation throttling. Decreasing memory (Option D) can actually worsen performance and increase execution time.

AWS documentation explicitly recommends reserved concurrency when workloads experience unpredictable or bursty invocation patterns and must run reliably. Therefore, reserving concurrency is the correct and AWS-recommended solution.

The correct answer is C because AWS AppConfig provides built-in support for feature flags , allowing developers to enable or disable features dynamically without redeploying application code. This is exactly what the question requires: keeping features hidden from end users until the features are ready for release, and then selectively activating them when appropriate.

AWS documentation describes AppConfig as a service for managing application configuration in a safe and controlled way. Feature flags in AppConfig let teams separate deployment from release , which is a core best practice in modern application development. A developer can deploy code that contains unfinished or hidden functionality, while the actual visibility and activation of that functionality is controlled through feature flag values stored in an AppConfig configuration profile. When the feature is ready, the flag can be turned on without changing the application package.

Option A is incorrect because AWS AppSync is a managed GraphQL service and is not the AWS feature flag service for application configuration management. Option B is incorrect because DynamoDB Streams are used for capturing item-level changes and reacting to table updates, not for controlled feature activation. Option D is incorrect because Amplify DataStore is intended for client-side data synchronization and offline access patterns, not centralized production feature flag management.

Using AppConfig also provides operational benefits such as deployment strategies, configuration validation, and rollback support, which make it safer than building a custom feature toggle mechanism. For these reasons, AWS AppConfig feature flags are the most appropriate and AWS-recommended solution for hiding prerelease features and selectively enabling them later.

Therefore, C is the correct answer.