FitFlow Membership Platform

Complete gym management system for memberships, billing, and operations

Planned Gym Operations

Problem Solved

Gym owners struggle to manage member lifecycles, recurring billing, and coach schedules manually. This creates friction in onboarding, payment failures, and scheduling conflicts. FitFlow automates the entire workflow.

Core Features

✓Member registration and profile management
✓Stripe integration for card payments with PCI compliance
✓Automatic subscription renewals with retry logic
✓Coach schedule booking system with availability
✓Member activity tracking and attendance logs
✓Admin dashboard for revenue insights
✓Email notifications for renewals and expiring memberships

Technical Architecture

┌─────────────────────────────────────┐
│       Angular Frontend (SPA)         │
│   - Member Portal                   │
│   - Coach Dashboard                 │
│   - Admin Console                   │
└──────────────┬──────────────────────┘
               │
      ┌────────┴────────┐
      │                 │
┌─────▼──────────────────▼──────┐
│   Spring Boot REST API        │
│   - Auth Service              │
│   - Member Service            │
│   - Subscription Engine        │
│   - Booking Service           │
└──────────────┬─────────────────┘
      ┌────────┴─────────┬─────────────┐
      │                  │             │
┌─────▼─────┐   ┌────────▼──┐   ┌─────▼──┐
│PostgreSQL │   │   Redis   │   │ Stripe │
│(Members,  │   │ (Cache)   │   │  API   │
│ Schedule) │   │           │   │        │
└───────────┘   └───────────┘   └────────┘

Tech Stack

Frontend

• Angular 21
• TypeScript
• RxJS
• TailwindCSS
• Stripe.js

Backend

• Java 17
• Spring Boot 3
• Spring Security
• JPA/Hibernate

Data & DevOps

• PostgreSQL
• Redis
• Docker
• AWS EC2

Technical Challenges

Subscription Renewal Logic

Built a robust state machine to handle subscription renewals with exponential backoff retry logic. When Stripe fails, the system retries with increasing delays and logs all attempts for audit purposes.

PCI Compliance & Payment Security

Never stored card data locally. Implemented server-side integration with Stripe using webhooks and idempotent API calls to prevent duplicate charges.

Future Improvements

→Mobile app for members to book classes on-the-go
→AI-powered coach recommendations based on member preferences
→Integration with fitness tracking APIs (Apple Health, Google Fit)
→Automated email sequences for member engagement
→Multitenancy support for gym chains

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