Reminder Service

A NestJS microservice (API + Worker) that powers timezone-aware appointment reminders for the MediPulso platform. When a patient books an appointment, the service schedules reminders and delivers them via Email/SMS (24h and 2h before the visit) using a resilient job queue.

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Features

• API + Worker separation – scale independently for clean isolation.
• Event-driven – consumes appointment.created and related events from MediPulso.
• Queue orchestration – Redis + BullMQ with delayed jobs, retries, priorities, and exponential backoff.
• Timezone-aware scheduling – powered by Luxon; clamps reminders to local windows (e.g. 10:00–19:00).
• Persistence – PostgreSQL + Prisma for appointments, schedules, and delivery logs.
• Email/SMS delivery – Nodemailer + MailHog in dev; SendGrid/Mailgun and Twilio in production.
• Observability – OpenTelemetry tracing/metrics, Prometheus/Grafana dashboards, Sentry error tracking.
• Secrets/config – .env in dev; Vault/SOPS or cloud secret manager in prod.
• Dockerized – production-ready container builds with health/readiness checks.

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Architecture

📂 Project Structure

reminder-service/
│
├── apps/
│   ├── reminder-api/     # API (accepts events, schedules reminders)
│   └── reminder-worker/  # Worker (processes queue, sends reminders)
│
├── prisma/
│   └── schema.prisma     # Postgres schema (appointments, schedules, delivery_log)
│
├── src/                  # Shared libs, DTOs, utils
│
├── docker/               # Dockerfiles and configs
│
├── .env.example          # Example environment variables
├── package.json
└── README.md


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##  Tech Stack

- **Backend**: [NestJS](https://nestjs.com/) + TypeScript
- **Database**: PostgreSQL + [Prisma](https://www.prisma.io/)
- **Queue**: Redis + [BullMQ](https://docs.bullmq.io/)
- **Date/Time**: [Luxon](https://moment.github.io/luxon/)
- **Email**: Nodemailer (dev) / SendGrid, Mailgun (prod)
- **SMS**: Twilio (prod)
- **Observability**: OpenTelemetry · Prometheus/Grafana · Sentry
- **Containers**: Docker

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##  Project Structure

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##  Development

Start API & Worker locally:

# API

npm run start:dev reminder-api

# Worker

npm run start:dev reminder-worker

brew install mailhog # macOS
mailhog

# Open: http://localhost:8025

## 🐳 Docker

Build & run services:

docker-compose up --build

##  Testing

npm run test
npm run test:e2e

## 📜 License

This project is licensed under the **MIT License**.

MIT © 2025 MediPulso Team