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Fitly - Full Stack Fitness Tracker App & Website

Fitly - Full Stack Fitness Tracker App & Website

Dec 2024 – Mar 2025
Live

About the Project

Fitly is a comprehensive, full-stack fitness tracker application that helps users log, view, and manage their workouts effortlessly. It leverages a robust Node.js/Express REST API with MongoDB for data management, while providing a seamless user experience across a React.js web frontend and a React Native (Expo) mobile application.

Technical Architecture

Frontend (Web)React.js (Vite, TailwindCSS)
Mobile ClientReact Native (Expo)
Backend APINode.js (Express.js) REST API
Database LayerMongoDB (NoSQL)
AuthenticationJSON Web Tokens (JWT) & Bcrypt
HostingProduction-ready Node.js environment

Core Features Breakdown

Workout Intelligence

  • Dynamic Logging: Track workout type, duration, date, and calories burned
  • Comprehensive History: View and manage all past exercise sessions
  • Real-time Updates: Instant logging and deletion across all devices
  • Exercise Management: Support for a wide variety of fitness activities

Multi-Platform Ecosystem

  • Web Frontend: High-performance React application built with Vite
  • Mobile App: Modern React Native (Expo) app for on-the-go tracking
  • Responsiveness: Fully optimized for desktop, tablet, and mobile viewers
  • Unified Data: Seamless performance and synchronization between platforms

Health & Progress Analytics

  • Summary Dashboard: Track total workouts, total time, and calorie milestones
  • Visual Progress: Intuitive UI for monitoring fitness journey over time
  • Goal Orientation: Data-driven insights to help users stay on track

Challenges & Solutions

Challenge

Syncing off-grid workout sessions when the user regains cellular connection

Solution

Implemented AsyncStorage queuing on the React Native wrapper to buffer API requests until a stable network handshake completes.

Challenge

Standardizing dynamic fitness data types (cardio, weights, yoga) in a unified UI

Solution

Built polymorphic Mongoose schemas combined with dynamic React rendering components mapped to activity types.

Security Posture

Secured Routes

JWT-protected API endpoints for user data privacy

Cryptographic Security

Robust password hashing using Bcrypt

Stateless Sessions

Token-based authentication for scalable cross-platform access

Live DemoSource Code

Tech Stack

React Native
Expo
React.js
Node.js
Express
MongoDB
Vite
TailwindCSS

Performance

QueueingSync Engine
ExpoMobile Tech
ViteWeb Framework
PolymorphicData Integrity

System Status

Availability99.9%
Deployment
CI/CD

"Built for scale and professional-grade security."

Interested in this project?

Let's discuss how we can build something amazing together based on this architecture.

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