Requirements

Let's refine our Stock Option Alerting System. We aim to build a system that allows users to define alerts on stock option prices. The system should monitor the market, trigger alerts when the specified conditions are met, and notify the user. This is a classic problem where thoughtful object-oriented design choices can lead to a robust, scalable, and maintainable solution. Think of the real-world implications. A trader might want to be notified when a specific option reaches a certain price, or when the implied volatility hits a predefined level. Our system should empower them to create and manage these alerts efficiently. This requires careful consideration of data structures, threading (if applicable), and overall system architecture. # Requirements ## Functional Requirements 1. **Alert Creation:** * Allow users to create alerts based on stock option attributes (e.g., ticker symbol, expiration date, strike price, option type - call/put). * Support different types of conditions: * Price-based alerts (e.g., "Option price >= $X", "Option price = A%", "Implied Volatility <= B%"). * Enable users to specify the alert triggering frequency (e.g., trigger once, trigger every time the condition is met). * Allow users to set alert expiration dates. * Implement validation to ensure that alerts have correct data. Handle invalid alert parameters gracefully (e.g., expiration date in the past, negative price threshold). * Support batch creation of alerts, optimizing for scenarios where users are setting up numerous alerts simultaneously. 2. **Alert Monitoring:** * Continuously monitor the market for options matching the user-defined alert criteria. * Efficiently retrieve option data (consider this as a feed from an external source). The system should be able to handle a high volume of incoming market data updates. * Evaluate alert conditions against the incoming market data. * Employ strategies to minimize the impact of monitoring on system performance. 3. **Alert Triggering and Notification:** * Trigger alerts when the specified conditions are met. * Support multiple notification channels (e.g., email, SMS, in-app notification). * Ensure that notifications are sent reliably. * Provide a mechanism to track the history of triggered alerts. 4. **Alert Management:** * Allow users to view their active alerts. * Enable users to modify existing alerts (e.g., change the price threshold, update the notification channel). * Permit users to delete alerts. * Implement pagination for large alert lists to improve UI responsiveness. 5. **Concurrency:** * Handle concurrent alert creation, modification, and deletion requests from multiple users. * Ensure thread-safe access to shared data structures. ## Non-Functional Requirements 1. **Thread Safety:** The system must be thread-safe to handle concurrent requests. Use appropriate synchronization mechanisms to prevent race conditions and data corruption. Consider lock granularity and alternatives to locking if performance becomes an issue. 2. **Extensibility:** The system should be easily extensible to support new types of alert conditions, notification channels, and data sources. Employ design patterns like Strategy or Factory to achieve this. 3. **Modularity:** The system should be composed of loosely coupled modules to promote maintainability and reusability. Each module should have a well-defined responsibility. 4. **Testability:** The system should be designed to be easily testable. Use dependency injection to facilitate unit testing and integration testing. Focus on writing comprehensive unit tests for critical components. 5. **Performance:** The system should be able to handle a large number of alerts and a high volume of market data updates without significant performance degradation. Employ efficient data structures and algorithms to minimize processing time. Consider the impact of synchronization on performance. 6. **Scalability:** The system should be scalable to accommodate a growing number of users and alerts. While full-blown distributed scaling isn't the *focus*, the *design* of the classes should facilitate future scaling. Can the Alert Monitoring component be easily distributed? 7. **Maintainability:** Code should be well-documented, easy to understand, and follow coding conventions. ## Core Entities 1. **StockOption:** Represents a stock option with attributes like ticker symbol, expiration date, strike price, and option type (call/put). This is a fundamental data object. 2. **Alert:** Represents an alert defined by a user. It contains information about the stock option to monitor, the condition to trigger the alert, the notification channel, and other relevant details. 3. **Condition:** An interface representing a condition that triggers an alert. Implementations could include `PriceCondition` and `VolatilityCondition`. This facilitates extensibility. 4. **PriceCondition:** A concrete implementation of the `Condition` interface for price-based alerts. It contains the price threshold and the comparison operator (e.g., >=, <=). 5. **VolatilityCondition:** A concrete implementation of the `Condition` interface for volatility-based alerts. 6. **NotificationChannel:** An interface representing a notification channel. Implementations could include `EmailNotificationChannel`, `SMSNotificationChannel`, and `InAppNotificationChannel`. 7. **EmailNotificationChannel:** A concrete implementation of the `NotificationChannel` interface for sending email notifications. 8. **SMSNotificationChannel:** A concrete implementation of the `NotificationChannel` interface for sending SMS notifications. 9. **AlertManager:** Manages the creation, modification, deletion, and monitoring of alerts. This is the central component of the system. 10. **MarketDataService:** A service that provides real-time market data for stock options. This could be an external service or a mock implementation for testing. 11. **AlertTrigger:** Responsible for evaluating alert conditions and triggering notifications when the conditions are met. 12. **UserRepository:** Manages User data.

Design System where User can create alerts on StockOptions.

Requirements

Interview Simulation

Functional Requirements

💡 Interview Tip

Non-Functional Requirements

Core Entity Identification

Premium Content