Requirements Document

Introduction

This feature enhances the existing AB testing library (libs/ab-test) to provide comprehensive AB testing capabilities for the Campus educational platform. The enhancement will add template rendering tools for displaying different variants to users and user journey tracking to measure the effectiveness of different test variants. This will enable data-driven decision making for UI/UX improvements across all Campus applications.

Requirements

Requirement 1

User Story: As a developer, I want to easily set up AB tests with different template variants, so that I can test different UI approaches without complex conditional logic in my components.

Acceptance Criteria

1. WHEN a developer defines an AB test configuration THEN the system SHALL provide a declarative way to specify multiple template variants
2. WHEN a user visits a page with an AB test THEN the system SHALL automatically assign them to a variant based on configured distribution weights
3. WHEN a variant is assigned to a user THEN the system SHALL persist this assignment for the duration of the test to ensure consistent experience
4. IF a user has been previously assigned to a variant THEN the system SHALL continue showing the same variant on subsequent visits
5. WHEN an AB test is configured THEN the system SHALL support percentage-based traffic allocation (e.g., 50/50, 70/30 splits)

Requirement 2

User Story: As a developer, I want Angular directives and components for AB test template rendering, so that I can easily integrate AB testing into existing components without major refactoring.

Acceptance Criteria

1. WHEN using the AB test directive THEN the system SHALL provide a structural directive that conditionally renders templates based on assigned variants
2. WHEN multiple variants are defined THEN the system SHALL only render the template corresponding to the user's assigned variant
3. WHEN a variant template is rendered THEN the system SHALL automatically track that the variant was shown to the user
4. IF no variant is assigned THEN the system SHALL render a default/control variant
5. WHEN using AB test components THEN the system SHALL provide wrapper components that handle variant logic internally

Requirement 3

User Story: As a product manager, I want to track user interactions and conversions for each AB test variant, so that I can measure which variant performs better.

Acceptance Criteria

1. WHEN a user interacts with an AB test element THEN the system SHALL track the interaction event with variant information
2. WHEN a conversion goal is reached THEN the system SHALL record the conversion against the user's assigned variant
3. WHEN tracking events THEN the system SHALL include timestamp, user session, variant ID, and event type
4. IF tracking is enabled THEN the system SHALL send tracking data to a configurable analytics endpoint
5. WHEN offline THEN the system SHALL queue tracking events and send them when connectivity is restored
6. WHEN multiple events occur THEN the system SHALL batch events for efficiency and reduced analytics endpoint load
7. WHEN sending events THEN the system SHALL use fire-and-forget approach to avoid blocking user interactions
8. WHEN events are sent to the API THEN the system SHALL support the data pipeline: API → Firehose → S3 storage → Redshift → PowerBI analytics

Requirement 4

User Story: As a developer, I want programmatic APIs for AB test management, so that I can dynamically control tests and retrieve variant assignments in my application logic.

Acceptance Criteria

1. WHEN calling the AB test service THEN the system SHALL provide methods to get current variant assignments for specific tests
2. WHEN programmatically tracking events THEN the system SHALL provide methods to record custom conversion events
3. WHEN managing test lifecycle THEN the system SHALL provide methods to start, pause, and end AB tests
4. IF a test is paused or ended THEN the system SHALL stop assigning new users to variants while maintaining existing assignments
5. WHEN retrieving test results THEN the system SHALL provide aggregated statistics for each variant

Requirement 5

User Story: As a product manager, I want to define and measure success metrics for AB test templates, so that I can determine which variant provides the best user experience and business outcomes.

Acceptance Criteria

1. WHEN defining an AB test THEN the system SHALL allow specification of primary and secondary success metrics (conversion rate, engagement time, click-through rate, task completion rate)
2. WHEN a success event occurs THEN the system SHALL record the event with contextual data (time to completion, user path, interaction sequence)
3. WHEN measuring template effectiveness THEN the system SHALL track user engagement metrics (time on page, scroll depth, interaction frequency, bounce rate)
4. WHEN storing AB test data THEN the system SHALL capture user behavior patterns (click heatmaps, form completion rates, navigation paths, error rates)
5. WHEN calculating success rates THEN the system SHALL provide statistical significance testing and confidence intervals
6. IF multiple success criteria exist THEN the system SHALL support weighted scoring and multi-objective optimization
7. WHEN analyzing results THEN the system SHALL provide cohort analysis capabilities (user segments, device types, geographic regions)
8. WHEN measuring user satisfaction THEN the system SHALL integrate with user feedback systems and implicit satisfaction signals

Requirement 6

User Story: As a developer, I want comprehensive user journey tracking, so that I can understand the complete user flow through different AB test variants.

Acceptance Criteria

1. WHEN a user navigates between pages THEN the system SHALL track page views with their current AB test variant assignments
2. WHEN user actions occur THEN the system SHALL record the action sequence with timing information
3. WHEN a user session includes multiple AB tests THEN the system SHALL track interactions across all active tests
4. IF a user's journey spans multiple sessions THEN the system SHALL maintain continuity of variant assignments and tracking
5. WHEN analyzing user journeys THEN the system SHALL provide funnel analysis capabilities for each variant

Requirement 7

User Story: As a system administrator, I want configurable AB test settings, so that I can control test behavior across different environments and applications.

Acceptance Criteria

1. WHEN configuring AB tests THEN the system SHALL support environment-specific settings (dev, staging, production)
2. WHEN setting up tracking THEN the system SHALL allow configuration of data retention policies
3. WHEN managing user privacy THEN the system SHALL provide options to anonymize or exclude sensitive data from tracking
4. IF GDPR compliance is required THEN the system SHALL respect user consent preferences for tracking
5. WHEN debugging tests THEN the system SHALL provide debug mode with detailed logging and variant assignment visibility

Requirement 8

User Story: As a developer, I want integration with existing Campus authentication and user management, so that AB tests work seamlessly with the current user system.

Acceptance Criteria

1. WHEN a user is authenticated THEN the system SHALL use stable user identifiers for consistent variant assignment
2. WHEN a user is anonymous THEN the system SHALL use browser-based identifiers with fallback mechanisms
3. WHEN user roles are defined THEN the system SHALL support role-based test inclusion/exclusion rules
4. IF user preferences exist THEN the system SHALL respect opt-out preferences for AB testing
5. WHEN integrating with existing services THEN the system SHALL use dependency injection tokens following Campus architecture patterns

Requirement 9

User Story: As a quality assurance engineer, I want testing utilities and mock services, so that I can reliably test AB test functionality in automated tests.

Acceptance Criteria

1. WHEN writing unit tests THEN the system SHALL provide mock services that simulate different variant assignments
2. WHEN testing components THEN the system SHALL provide test utilities to force specific variant rendering
3. WHEN running E2E tests THEN the system SHALL provide methods to control AB test behavior deterministically
4. IF test isolation is needed THEN the system SHALL provide utilities to reset AB test state between tests
5. WHEN debugging tests THEN the system SHALL provide clear error messages and debugging information