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Creating an Order Processing System with Lambda Durable Functions

Prerequisites

Create the Source Code Files

Create the following files in your project directory:

Function Code

# NEED: Verify correct imports
import boto3
import json

def lambda_handler(event, context):
    # NEED: Verify DurableContext syntax
    durable = context.durable
    
    try:
        # Validate and store order
        order = await durable.step('validate', async () => {
            return validate_order(event['order'])
        })
        
        # Process payment
        # NEED: Verify wait syntax
        await durable.wait(/* wait configuration */)
        
        # Additional steps
        # NEED: Complete implementation
        
    except Exception as e:
        # NEED: Error handling patterns
        raise e

def validate_order(order_data):
    # NEED: Implementation
    pass

Requirements File

# NEED: List of required packages

Deploy the App

Create a DynamoDB Table for Orders

Create the Lambda Function

Create the API Gateway Endpoint

Test the App

Submit a test order:

{
    "orderId": "12345",
    "items": [
        {
            "productId": "ABC123",
            "quantity": 1
        }
    ]
}

NEED: Add specific monitoring instructions for Durable Functions

Next Steps

Add Business Logic

Implement inventory management:

async def check_inventory(order):
    # Add inventory check logic
    pass

Add price calculations:

async def calculate_total(order):
    # Add pricing logic
    pass

Improve Error Handling

Add compensation logic:

async def reverse_payment(order):
    # Add payment reversal logic
    pass

Handle order cancellations:

async def cancel_order(order):
    # Add cancellation logic
    pass

Integrate External Systems

async def notify_shipping_provider(order):
    # Add shipping integration
    pass

async def send_customer_notification(order):
    # Add notification logic
    pass

Enhance Monitoring