Build Real-time Notification & Alert System

[akargi]

Overview

Implement a comprehensive notification system that delivers real-time alerts to users through multiple channels (in-app, email, SMS) for trading events, price movements, order executions, and system updates.

Description

Users need immediate notification of critical trading events including order fills, price alerts, portfolio threshold breaches, and system maintenance notices.

Requirements

• Notification types: order updates, price alerts, portfolio alerts, system notices
• Multiple delivery channels: in-app push, email, SMS (configurable per user)
• User notification preferences and opt-in/opt-out control
• Real-time in-app notifications using WebSocket
• Email templates with transaction details
• SMS templates with concise information
• Notification history and read/unread status
• Batch notification delivery for efficiency
• Scheduled notification delivery support
• Retry logic for failed delivery attempts

Acceptance Criteria

• Notification entity and preference models created
• Event-driven architecture using NestJS EventEmitter for notification triggers
• WebSocket integration for real-time in-app notifications
• POST /api/notifications/preferences endpoint for user settings
• GET /api/notifications returns paginated notification history
• Email service integration with template rendering
• SMS service integration (Twilio or similar)
• Notification delivery within 1 second of triggering event
• Unit tests for notification service (>85% coverage)
• E2E tests validate multi-channel delivery
• Failed notifications logged and retried up to 3 times