Use Node.js with Express, the Infobip API, and node-cron to build an SMS reminder system. Create an API endpoint to handle reminder requests and a scheduler to check for due reminders and dispatch them via Infobip.

The Infobip Node.js SDK simplifies interaction with the Infobip SMS API, allowing you to easily send SMS messages from your Node.js application. It handles authentication, request formatting, and response parsing.

Prisma is a next-generation ORM that streamlines database operations in Node.js. It provides type safety, schema migrations, and an intuitive API for querying and updating the PostgreSQL database where reminder information is stored.

If your reminder system operates in a high-concurrency or distributed environment, a more robust locking mechanism like Redis is recommended to prevent race conditions when multiple scheduler instances might run concurrently.

While the article uses PostgreSQL, you could adapt the system to use other databases by configuring the appropriate Prisma data source and adjusting database interaction code in the scheduler and controller.

You'll need an Infobip account and an API key. Obtain these from the Infobip portal under Developers -> API Keys, then store them securely as environment variables (INFOBIP_API_KEY and INFOBIP_BASE_URL).

Node-cron is a task scheduling library that enables periodic execution of functions within your Node.js application. It is used to trigger the check for due reminders at defined intervals.

The project's Infobip service constructs a payload with recipient number and message text, then uses the Infobip Node.js SDK's send() method to make the API call, handling successful submissions or potential errors.

The example uses a basic API key for authentication. However, for production, stronger methods like JWT or OAuth2 are recommended. Implement appropriate authentication middleware to protect the endpoint.

E.164 is an international standard for phone number formatting. It includes a '+' sign followed by the country code and national number without spaces or punctuation, ensuring consistency for global SMS delivery.

Node-cron uses a cron expression format (e.g., ' ' for every minute, or '/5 ' for every 5 minutes). See the node-cron documentation for advanced scheduling patterns.

Implement a retry mechanism in the scheduler job’s catch block. If sending via the primary SMS service fails, store retry attempts in the database and re-attempt sending up to a defined limit.

The scheduler job handles failures by updating the reminder status in the database to 'FAILED'. Detailed error information is logged for debugging. Consider a fallback strategy or retry mechanism to improve reliability.

You need Node.js v18+, access to a PostgreSQL database, an active Infobip account with API credentials, and familiarity with Node.js, Express, and APIs.