A/B Testing Service for Sophra

The ABTestingService is a sophisticated component within the Sophra system, designed to facilitate complex A/B testing scenarios with real-time metrics calculation and statistical analysis. This service integrates seamlessly with Sophra’s core architecture, leveraging the Prisma ORM for efficient data management and persistence. It provides a comprehensive suite of functionalities for creating, managing, and analyzing A/B tests, supporting Sophra’s commitment to data-driven decision making and continuous optimization.

At its core, the ABTestingService employs a robust variant assignment algorithm that ensures statistically valid distribution of users across test variants. This is achieved through a combination of random assignment and persistent user tracking, allowing for consistent user experiences throughout the duration of a test. The service’s architecture is designed to handle high-volume traffic, with optimized database queries and caching strategies to maintain performance under load.

One of the key architectural decisions in the ABTestingService is the use of a flexible configuration model. This allows for dynamic test setups, supporting various metrics and custom weighting systems for different test scenarios. The service’s modular design facilitates easy extension and customization, enabling Sophra to adapt to evolving testing requirements without significant refactoring.

Performance is a critical consideration in the ABTestingService implementation. The service utilizes batch processing for metric calculations and employs efficient data structures for rapid retrieval of test configurations and user assignments. This approach minimizes database load and ensures responsive performance even for large-scale tests with millions of participants.

A unique feature of the ABTestingService is its advanced statistical analysis capabilities. The service not only tracks basic conversion metrics but also calculates statistical significance, confidence intervals, and supports time-series analysis. This empowers Sophra users to make data-driven decisions with a high degree of confidence, backed by robust statistical methodologies.

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Exported Components

interface ABTestVariant {
  id: string;          // Unique identifier for the variant
  name: string;        // Human-readable name for the variant
  allocation: number;  // Percentage of traffic allocated to this variant (0-1)
  weights: Record<string, number>;  // Custom weighting factors for the variant
}

The ABTestingService class extends BaseService and provides the following key methods:

async createTest(params: CreateABTestParams): Promise<ABTest>

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Implementation Examples

const abTestingService = new ABTestingService({ environment: 'production' });

const testConfig: CreateABTestParams = {
  name: 'New Homepage Layout Test',
  description: 'Testing the conversion rate of a new homepage design',
  startDate: new Date(),
  endDate: new Date(Date.now() + 30 * 24 * 60 * 60 * 1000), // 30 days from now
  status: ExperimentStatus.ACTIVE,
  configuration: {
    variants: [
      { id: 'control', name: 'Control', allocation: 0.5, weights: {} },
      { id: 'variant_a', name: 'New Design', allocation: 0.5, weights: {} }
    ],
    metrics: {
      primary: 'conversion_rate',
      secondary: ['bounce_rate', 'time_on_page']
    }
  }
};

const createdTest = await abTestingService.createTest(testConfig);
console.log('Created A/B Test:', createdTest);

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Sophra Integration Details

The ABTestingService integrates with other Sophra components through the following patterns:

1. Authentication Service: User sessions are validated before variant assignment.
2. Analytics Engine: Conversion events are forwarded for broader analysis.
3. Search Service: A/B test results can influence search result rankings.

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Error Handling

The ABTestingService implements comprehensive error handling:

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Data Flow

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Performance Considerations

The ABTestingService employs several optimization strategies:

• Caching: Variant assignments are cached in Redis for fast retrieval.
• Batch Processing: Metric calculations are performed in batches during off-peak hours.
• Indexing: Database indices are optimized for common query patterns.

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Security Implementation

async function authenticateRequest(req: Request): Promise<User | null> {
  const token = req.headers.authorization?.split(' ')[1];
  if (!token) return null;
  
  try {
    const user = await verifyJWT(token);
    return user;
  } catch (error) {
    logger.error('Authentication failed', { error });
    return null;
  }
}

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Configuration

The ABTestingService can be configured using the following environment variables:

AB_TEST_DB_URL=postgresql://user:password@host:5432/abtest_db
AB_TEST_CACHE_URL=redis://localhost:6379
AB_TEST_MAX_VARIANTS=5
AB_TEST_SIGNIFICANCE_THRESHOLD=0.05