CompletedNext.jsNode.jsTypeScript+5 more
Habit Pulse
A full-stack habit tracker SaaS with OTP login, reminders, analytics, and subscription payments.
Timeline
2 Months
Role
Full Stack Developer
Team
Solo
Status
CompletedTechnology Stack
Next.js
Node.js
TypeScript
MongoDB
Tailwind CSS
Firebase
Razorpay
Cloud Messaging
Key Challenges
- Reminder Notifications
- Recurring Subscriptions
- Database Optimization
- Real-time Sync
Key Learnings
- Firebase Cloud Messaging
- Razorpay Subscriptions
- MongoDB Indexing
- SaaS Architecture
Overview
Habit Pulse is a full-stack SaaS habit-tracking platform built with Next.js, Node.js, MongoDB, and Firebase Cloud Messaging.
It includes secure OTP login, daily reminders, analytics dashboards, and subscription plans powered by Razorpay.
The goal was to build a production-ready habit-tracking tool with clean UI, fast performance, and smooth onboarding.
Key Features
Authentication
- Secure OTP login using Firebase
- Automatic session management
- Fast onboarding optimized for mobile
Habit Management
- Create, update, and delete habits
- Track daily, weekly, and monthly progress
- Visual analytics for streaks and completion rates
Notifications
- Real-time reminders using Firebase Cloud Messaging
- Custom reminder timings per habit
- High-delivery notifications with fallback handling
Payments
- Razorpay recurring subscription integration
- Automatic plan activation & renewal
- Webhooks for billing events
Performance
- Optimized MongoDB schemas with compound indexes
- Query performance improved by nearly 50%
- Cached API responses for faster sync
API Endpoints
Habit Endpoints
GET /api/habits
POST /api/habits
PATCH /api/habits/:id
DELETE /api/habits/:id
Notification Service
### *Subscription Endpoints*
```ts
POST /api/subscribe/create-plan
POST /api/subscribe/webhook
GET /api/subscribe/status
## Challenges
### 1. Implementing reliable push notifications
Ensuring reminders reached every device required several layers of reliability:
- Token rotation handling
- Background delivery compatibility
- Retry queues for failed deliveries
### 2. Designing subscription billing
Razorpay integration involved multiple moving parts:
- Secure signature verification for every transaction
- Webhooks for retries, failures, and renewals
- Persistent subscription states stored in the database
### 3. Optimizing database reads
Large datasets caused slow queries.
Adding **compound indexes** improved read performance by nearly **50%**.
## What I Learned
- Building SaaS-ready authentication + subscription systems
- Implementing real-world push notifications using FCM
- Database indexing & optimization techniques
- Structuring scalable APIs and folder architecture
- Deploying production-ready applications with analytics and monitoring