A great backend application doesn't just store data in a database; it communicates with the outside world. Whether it's a welcome email, a password reset, or a notification for a new feedback, knowing how to integrate an email service is a crucial skill for any developer. In this article, I’ll show you how I integrated email notifications into my Feedback API using Nodemailer and the Provider Pattern . The Goal When a user submits feedback, the system should: Validate the data. Save it to the database. Notify the administrator via email. Architecture Matters: The Provider Pattern Instead of hardcoding Nodemailer directly into my business logic, I used the Provider Pattern . This keeps the code decoupled. If I decide to switch from Nodemailer to AWS SES or SendGrid in the future, I only need to change one file. 1.…