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Event-Driven APIs with StateSet One

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Core Architecture Principles

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Three-Factor App Architecture with Durable Execution OS

• Single-Point GraphQL API: A unified interface for data interactions, providing remote data joins.
• Event Triggers and Webhooks: Enable seamless integrations and automation through event-driven logic.
• Realtime Search: Provides customer service and warehouse operations with efficient data access.
• Data Validation and Synchronization: Maintains data integrity and consistency.
• Workflow Orchestration: Manages complex business processes using Temporal.
• Automated Processes: Automates routine tasks such as label printing and refund processing.
• Comprehensive Testing: Ensures quality through rigorous QA testing for all serverless functions.

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Three Factors of StateSet Architecture

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Factor #1: Realtime GraphQL API

• Low-Latency Responses: GraphQL ensures that state changes provide immediate feedback to the user.
• GraphQL Subscriptions: Enables real-time data streaming, eliminating the need for polling and improving scalability.

  A client application sends a GraphQL query to the API which then fetches the data from its underlying data sources.

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Factor #2: Reliable Eventing System

• Atomic Operations: State changes and event generation are atomic, ensuring consistency.
• At-Least-Once Delivery: Guarantees that events are delivered to consumers, allowing a complete state history for observability.

  When a state change happens, it is sent to the event bus and then picked up by the configured event handlers.

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Factor #3: Asynchronous Serverless Functions

• Idempotent Functions: Functions can handle duplicate events without creating inconsistencies.
• Out-of-Order Event Handling: Functions handle events reliably, regardless of the order of arrival.

  An event is received by a serverless function which then executes an action.

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Detailed Architecture Components

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Three-Factor App with Durable Execution OS

• Modular Design: Business domains are separated into distinct services, allowing independent development and deployment.
• Durable Execution OS: Ensures workflows and state transitions are reliable, preventing data loss, and enabling recovery from failures.

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Single-Point GraphQL API

• Remote Data Joins: Combines data from multiple sources into a single API request, reducing network calls.
• Flexible Queries: Clients can request specific data, optimizing performance.

The GraphQL API combines data from multiple sources into a single response.

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Event Triggers and Webhooks

• Seamless Integrations: Connects with external systems and services.
• Automated Workflows: Enables event-driven automated processes.

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Realtime Search Capabilities

• Customer Service: Enables quick access to customer information for support teams.
• Warehouse Operations: Facilitates efficient inventory and order management.

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Data Validation and Synchronization

• Comprehensive Validation: Validates incoming data to prevent errors.
• Synchronization Mechanisms: Keeps data consistent across all systems.

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Workflow Orchestration with Temporal

• Complex Workflow Management: Orchestrates intricate business processes with ease.
• Automated Execution: Ensures workflows are reliably executed and can recover from failures.

  An event triggers a temporal workflow. The workflow then coordinates multiple activities

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Automated Processes

• Label Printing: Automatically generates and prints shipping labels for various regions.
• Refund Processing: Streamlines refund handling for quick and accurate transactions.

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Comprehensive Testing and QA

• Test QA Paths: Rigorous testing for all serverless functions.

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Event Handling

exports.handler = async (event) => {
  console.log('Received event:', JSON.stringify(event, null, 2));

  try {
    // Extract event data
    const { type, payload } = event;

    if (type === 'order.created') {
        // Process Order Created Event
      console.log('Processing order creation:', payload);
      // Add business logic to perform when order is created
      // ...
    }
        else if (type === 'return.created') {
        // Process Return Created Event
        console.log('Processing return creation:', payload);
        // Add business logic to perform when return is created
        // ...
        }
    else if (type === 'inventory.updated') {
        // Process Inventory Updated Event
        console.log('Processing inventory update:', payload);
        // Add business logic to perform when inventory is updated
        // ...
    }
      else {
         console.log('Unknown Event Type')
      }

    return {
      statusCode: 200,
      body: JSON.stringify({ message: 'Event processed successfully' }),
    };
  } catch (error) {
    console.error('Error processing event:', error);
    return {
      statusCode: 500,
      body: JSON.stringify({ message: 'Error processing event' }),
    };
  }
};

This is an example of a serverless function that can handle multiple different events. The function will check for the event type, extract the payload, perform the business logic, and then return a response.

The diagram shows the high level interactions between the different parts of the system.

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Conclusion