Use a Standard workflow with a parallel state started directly by an EventBridge rule on S3 object creation

DOP-C02 By islever Editorial Last updated

Implement deployment strategies for instance, container, and serverless environments. Manage event sources to process, notify, and take action in response to events.

Short answer

AD A Standard workflow with a parallel state, started directly by an EventBridge rule on S3 object creation.

Question

A company runs an application that stores artifacts in an Amazon S3 bucket. The application has a large user base. The application writes a high volume of objects to the S3 bucket. The company has enabled event notifications for the S3 bucket. When the application writes an object to the S3 bucket, several processing tasks need to be performed simultaneously. The company's DevOps team needs to create an AWS Step Functions workflow to orchestrate the processing tasks. Which combination of steps should the DevOps team take to meet these requirements with the LEAST operational overhead? (Choose two.)
  1. Create a Standard workflow that contains a parallel state that defines the processing tasks. Create an Asynchronous Express workflow that contains a parallel state that defines the processing tasks. Correct Answer
  2. Create a Synchronous Express workflow that contains a map state that defines the processing tasks.
  3. Create an Amazon EventBridge rule to match when a new S3 object is created. Configure the EventBridge rule to invoke an AWS Lambda function. Configure the Lambda function to start the processing workflow.
  4. Create an Amazon EventBridge rule to match when a new S3 object is created. Configure the EventBridge rule to start the processing workflow. Correct Answer

Key Takeaways

EventBridge can target a Step Functions state machine directly, so the workflow can be started without a bridging Lambda, which is what minimizes overhead and matches the already-configured S3 event notifications (D). The concurrency requirement maps to a parallel state (A). A Standard workflow is the appropriate type because it supports long-running executions up to one year with durable execution and CloudTrail-based auditability, which suits per-object processing pipelines; a Synchronous Express workflow in option B uses a map state, which iterates over items rather than running tasks in parallel, so it does not express the requirement.

The S3 bucket already emits event notifications and the pipeline must orchestrate several processing tasks that run simultaneously for each object. An EventBridge rule matching new S3 object creation events can start a Step Functions workflow directly through EventBridge target support, so no intermediate Lambda is needed. Within the workflow, a Standard workflow containing a parallel state expresses the concurrent processing tasks, and Standard workflows are the recommended type for long-running, durable, and auditable orchestration.

Common mistake: Using a Synchronous Express workflow with a map state (B) — a map state iterates over an array of items sequentially or with limited concurrency, whereas several tasks must run simultaneously, which requires a parallel state. Adding an extra Lambda between EventBridge and the workflow (C) — EventBridge can invoke a Step Functions workflow directly, so a Lambda adds code and cost without adding capability. Using an Asynchronous Express workflow (part of A) — Express workflows are intended for high-volume, short-duration processing rather than durable long-running orchestration.

Expert Analysis

Why the Answer Is Correct

Two requirements drive the design. First, several processing tasks must run simultaneously for each new object, which in Step Functions is expressed with a parallel state; the Standard workflow in option A is the right container because Standard workflows support long-running, durable executions of up to one year with full execution auditability, which suits a per-object processing pipeline (A). Second, the bucket already emits event notifications and the orchestration should start with the least operational overhead: an EventBridge rule matching new S3 object creation events can target a Step Functions state machine directly, so the workflow is started without a Lambda in between (D). A and D together deliver concurrent, event-driven orchestration with no custom bridging code.

Why the Other Options Are Wrong

B uses a Synchronous Express workflow containing a map state. A map state iterates over the items of an array, which is not the construct for running several independent tasks at the same time; concurrency across tasks requires a parallel state. Synchronous Express workflows are also limited to five minutes and are intended for high-volume short processing, not durable orchestration. C adds an EventBridge rule that invokes a Lambda function which then starts the workflow. Because EventBridge supports Step Functions state machines as a target directly, the Lambda adds code, cost, and a failure point without adding any capability. The Asynchronous Express workflow mentioned in option A is likewise the wrong workflow type for long-running durable processing. A and D are the correct combination.

Community Comment Notes

Community voted A,D (78). teo2157 explained the reasoning in two parts, noting the misspelling in option B and that Standard workflows are recommended for long-running, durable, auditable workflows. luisfsm_111 selected A and D specifically because of the parallel task processing requirement. tinyshare preferred B on the theory that Express suits high volume, but Express workflows do not support the parallel-state construct the requirement needs and are limited to short executions.

Official Reference

https://docs.aws.amazon.com/step-functions/latest/dg/connect-s3.html

This link opens the official vendor documentation in a new tab.

Community Votes

AD
100%

100% of anonymous learners picked answer AD. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 6 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 6

  1. teo2157 👍 2
    There's a misspelling and the option B is included in the option A, said that, going for standard workflow as it's recommended for long-running (up to one year), durable, and auditable workflows instead of Express Workflows that are ideal for high-volume, event-processing workloads such as IoT data ingestion, streaming data processing and transformation, and mobile application backends and can run for up to five minutes. .
  2. uncledana 👍 2
    Use a Standard Step Functions workflow with parallel states to handle the processing tasks (Option A). Use an EventBridge rule to directly trigger the Step Functions workflow (Option D).
  3. luisfsm_111 👍 2
    Because of the requirement for parallel task processing, I vote for A and D.
  4. Srikantha 👍 1
    ✅ A. Create a Standard workflow that contains a parallel state that defines the processing tasks. Standard workflows in AWS Step Functions are best suited for long-running, durable processes and support parallel states, which are perfect for triggering multiple tasks simultaneously. Since the processing involves several tasks, this structure provides reliability, retries, and observability out of the box. ✅ D. Create an Amazon EventBridge rule to match when a new S3 object is created. Configure the EventBridge rule to start the processing workflow. EventBridge can directly invoke a Step Functions workflow (without needing an intermediate Lambda function), which reduces operational overhead. It simplifies the event-driven architecture by removing custom code and improves maintainability.
  5. teo2157 👍 1 Answered D
    Changing my mind, as I said previously, there's a misspelling but the problem is that " Create an Asynchronous Express workflow that contains a parallel state that defines the processing tasks. " should be a separate option as it's the correct first part. D is pretty evident.
Show 1 more comment
  1. tinyshare 👍 1
    Standard workflow is for long-running. Express workflow is for high-volume. So B is better than A. https://docs.aws.amazon.com/step-functions/latest/dg/choosing-workflow-type.html

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