Requirements

Imagine you're building a platform akin to Pendo or Appcues. These platforms allow product managers to create and deploy in-app experiences like tooltips, onboarding flows, and announcements without requiring engineering changes to the core application. Our system needs to be flexible enough to support a wide variety of experience types, target specific user segments, track engagement metrics, and ensure smooth performance within the host application. The core challenge lies in designing a system that balances flexibility and maintainability. We need to support a growing range of experience types without constant code modifications, and we need to target these experiences precisely based on user attributes and application state. Furthermore, we must avoid impacting the performance of the host application and ensure experiences are displayed correctly and consistently. # Requirements ## Functional Requirements 1. **Experience Definition:** * Support defining different types of experiences (e.g., Tooltip, Modal, Slider, Announcement). Each experience type should have a configurable set of properties (e.g., text, position, colors, images, button actions). * Allow creating complex experiences composed of multiple steps or elements. * Provide a mechanism for defining custom experience types beyond the built-in ones. * Support versioning of experiences to enable A/B testing and rollback capabilities. 2. **Targeting:** * Enable targeting experiences to specific user segments based on attributes like user ID, role, subscription tier, location, and custom properties. * Allow targeting based on application state (e.g., current page, feature usage, user actions). * Support combining multiple targeting rules using logical operators (AND, OR, NOT). * Provide a preview mode to verify targeting rules before deploying an experience. 3. **Delivery:** * Provide a Javascript API for the host application to request and display experiences. * Support asynchronous loading of experience content to avoid blocking the main thread of the host application. * Implement a caching mechanism to reduce latency and network traffic. * Handle conflicts between multiple experiences targeting the same user and location. 4. **Analytics:** * Track key engagement metrics such as impressions, clicks, completions, and dismissals. * Provide a reporting interface to visualize experience performance and identify areas for improvement. * Support custom event tracking to capture specific user interactions within an experience. * Integrate with existing analytics platforms (e.g., Google Analytics, Mixpanel). 5. **Content Management:** * Provide an interface for managing experiences (create, edit, delete, publish, unpublish). * Support collaboration features such as user roles and permissions. * Offer a library of reusable components and templates. * Integrate with a content delivery network (CDN) for efficient content distribution. ## Non-Functional Requirements 1. **Extensibility:** The system should be easily extensible to support new experience types, targeting criteria, and analytics integrations without requiring major code changes. This includes the ability to add new rendering engines for different platforms. 2. **Modularity:** The system should be composed of loosely coupled modules to improve maintainability and testability. Each module should have a well-defined interface and a clear responsibility. 3. **Performance:** The system should minimize the impact on the performance of the host application. Experience loading and rendering should be asynchronous and optimized for speed. The system should handle a large number of concurrent users and experiences. 4. **Testability:** The system should be designed to facilitate unit, integration, and end-to-end testing. All modules should have well-defined interfaces that can be easily mocked or stubbed. 5. **Thread Safety:** The system should be thread-safe to handle concurrent requests from multiple users. Any shared state must be protected using appropriate synchronization mechanisms. Given that experience evaluation and delivery might happen concurrently, thread safety is paramount. 6. **Configuration:** The platform should allow for central configuration of all experiences. This should avoid having the client application be tightly coupled to individual experience definitions. ## Core Entities 1. **Experience:** Represents a single in-app experience. It contains information about the experience type, content, targeting rules, and analytics settings. 2. **ExperienceType:** Defines the type of experience (e.g., Tooltip, Modal, Slider). It specifies the properties required for that type and the rendering logic. 3. **TargetingRule:** Represents a rule for targeting experiences to specific users or application states. It contains information about the attribute to target, the operator to use (e.g., equals, greater than), and the value to match. 4. **User:** Represents a user of the host application. It contains information about the user's attributes, such as user ID, role, and subscription tier. 5. **ApplicationContext:** Represents the state of the host application. It contains information about the current page, feature usage, and user actions. 6. **AnalyticsTracker:** Interface for tracking engagement metrics. Concrete implementations handle integration with different analytics platforms. 7. **ExperienceRenderer:** Responsible for rendering the experience in the host application. Different renderers can be implemented for different platforms (e.g., web, mobile). 8. **ExperienceManager:** Orchestrates the entire process, from retrieving experiences to evaluating targeting rules and displaying the experiences.

Design product experience platform like pendo.

Requirements

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Functional Requirements

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Non-Functional Requirements

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