Step Functions for workflows in AWS - Mini Project: Build & Apply

Step Functions for workflows

📖 Scenario: You are building a simple workflow to automate a package delivery process using AWS Step Functions. The workflow will have steps to check package availability, process payment, and confirm shipment.

🎯 Goal: Create an AWS Step Functions state machine definition in JSON that models the package delivery workflow with three states: CheckAvailability, ProcessPayment, and ConfirmShipment. The workflow should proceed from checking availability to payment processing, then to shipment confirmation, and finally end successfully.

📋 What You'll Learn

Define a state machine with three states named exactly: CheckAvailability, ProcessPayment, and ConfirmShipment.

Each state should be a Task state with a placeholder resource ARN.

The workflow should start at CheckAvailability.

The states should transition in order: CheckAvailability -> ProcessPayment -> ConfirmShipment.

The ConfirmShipment state should be a terminal state with End set to true.

💡 Why This Matters

🌍 Real World

Step Functions help automate complex workflows by connecting multiple AWS services in a reliable sequence.

💼 Career

Understanding Step Functions is essential for cloud engineers and developers building scalable, serverless applications.

1

Create the initial state machine structure

Create a JSON object called stateMachine with a StartAt property set to CheckAvailability and an empty States object.

AWS

{
  "StartAt": "CheckAvailability",
  "States": {
    
  }
}
# Your code here

Need a hint?

Start by defining the StartAt property and an empty States object inside your JSON.

2

Add the CheckAvailability state

Inside the States object, add a state named CheckAvailability with Type set to Task, a placeholder Resource ARN string "arn:aws:lambda:region:account-id:function:CheckAvailability", and Next set to ProcessPayment.

AWS

{
  "StartAt": "CheckAvailability",
  "States": {
    
    // Add CheckAvailability state here
  }
}
# Your code here

Need a hint?

Remember to use the exact state name and set Next to ProcessPayment.

3

Add the ProcessPayment state

Add a state named ProcessPayment inside States with Type set to Task, Resource ARN "arn:aws:lambda:region:account-id:function:ProcessPayment", and Next set to ConfirmShipment.

AWS

{
  "StartAt": "CheckAvailability",
  "States": {
    "CheckAvailability": {
      "Type": "Task",
      "Resource": "arn:aws:lambda:region:account-id:function:CheckAvailability",
      "Next": "ProcessPayment"
    },
    
    // Add ProcessPayment state here
  }
}
# Your code here

Need a hint?

Use the exact state name and set Next to ConfirmShipment.

4

Add the terminal ConfirmShipment state

Add a state named ConfirmShipment inside States with Type set to Task, Resource ARN "arn:aws:lambda:region:account-id:function:ConfirmShipment", and End set to true to mark the workflow completion.

AWS

{
  "StartAt": "CheckAvailability",
  "States": {
    "CheckAvailability": {
      "Type": "Task",
      "Resource": "arn:aws:lambda:region:account-id:function:CheckAvailability",
      "Next": "ProcessPayment"
    },
    "ProcessPayment": {
      "Type": "Task",
      "Resource": "arn:aws:lambda:region:account-id:function:ProcessPayment",
      "Next": "ConfirmShipment"
    },
    
    // Add ConfirmShipment state here
  }
}
# Your code here

Need a hint?

Set End to true to mark this as the final state.