Building a Full Stack Productivity App with Task Manager, WhatsApp Reminders & Expense Tracking (Node.js + MongoDB)

Introduction- To improve productivity and build a real-world backend system, I developed a full stack productivity application that allows users to manage tasks, store notes, track expenses, and receive WhatsApp reminders for important tasks. The goal was to design a scalable backend architecture with secure authentication, structured database schemas, and third-party API integration. Key Features- User registration and login using JWT authentication Task management (Create, Update, Delete) WhatsApp reminder integration for tasks Notes storage using MongoDB Expense tracking system Protected routes using middleware. Tech Stack Used- React.js (Frontend) Node.js Express.js MongoDB Mongoose JWT Authentication REST APIs Postman for API testing Backend Architecture The backend was built using Express.js following a RESTful architecture. I implemented: JWT-based authentication system Middleware for protected routes Separate MongoDB schemas for Users, Tasks, Notes, and Expenses Controller and