DVA-C02 Development with AWS Services Practice Question
A Step Functions workflow calls three independent Lambda functions and should continue only after all results are available. Which state pattern should be used?
⚠ Common exam trap
Many exam-takers confuse the Parallel state with the Map state, but the Map state is for processing items in an array with the same logic, not for running distinct independent tasks.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Parallel state
The Parallel state in AWS Step Functions is designed to execute multiple branches of work concurrently and then aggregate their outputs into a single array. This is exactly what is needed when three independent Lambda functions must all complete before the workflow continues, as the Parallel state waits for all branches to finish before proceeding to the next state.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Choice state
Why it's wrong here
A Choice state in AWS Step Functions allows the workflow to transition to different states based on conditional logic applied to the input data. While it enables branching, it executes only one path at a time, making it unsuitable for concurrently invoking multiple independent Lambda functions. It would require sequential execution of each Lambda or complex nesting, which defeats the purpose of parallel execution for independent tasks.
- ✗
Wait state
Why it's wrong here
A Wait state pauses the execution of a Step Functions workflow for a specified duration or until a specific timestamp. Its primary function is to introduce delays or schedule future actions, not to initiate concurrent operations. Using a Wait state would halt the workflow's progress, preventing any simultaneous invocation of independent Lambda functions, as the workflow would simply pause before proceeding to the next sequential step.
- ✓
Parallel state
Why this is correct
The Parallel state is specifically designed to execute multiple independent branches of a workflow concurrently. Each branch within a Parallel state runs simultaneously, allowing for the efficient, parallel invocation of services like AWS Lambda functions. The state completes only when all its branches have finished their execution, aggregating their outputs into a single result, which perfectly addresses the requirement of calling three independent Lambda functions at the same time.
- ✗
Fail state
Why it's wrong here
A Fail state immediately terminates the execution of a Step Functions workflow and marks it as failed. Its purpose is to signal an unrecoverable error or an intentional failure point within the workflow logic. Using a Fail state would prevent any Lambda functions from being called successfully, let alone in parallel, as it halts all processing rather than orchestrating concurrent tasks.
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DVA-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DVA-C02 exam.