Proposal
1. Project Overview
MyFit is a comprehensive technology platform designed to support users throughout their health management and fitness journey. To deliver a smooth and reliable experience, the system is built on three core foundations:
- User Experience (Frontend): An intuitive and user-friendly interface that allows users to easily track progress, personal metrics, and interact with features.
- Core Processing System (Backend): A powerful data processing platform ensuring accuracy, real-time synchronization, and maximum data security.
- Cloud Infrastructure: Fully deployed on AWS cloud infrastructure.
By leveraging Cloud Managed Services, MyFit:
- Optimizes operational costs
- Ensures 24/7 system availability
- Supports seamless scalability as user demand grows
2. Objectives
2.1 Overall Objectives:
- Build a fitness application supporting both mobile and web platforms.
- Ensure stable operation on AWS infrastructure.
- Guarantee availability and scalability based on cloud resources.
- Provide a seamless user experience from login to health tracking.
- Establish a clear, repeatable deployment process to reduce operational errors.
2.2 Specific Deliverables:
- Backend API secured using JWT and Cognito
- Frontend served via CloudFront for fast and stable delivery
- Health and workout tracking dashboard
- Separate deployment pipelines for infrastructure and application with rollout monitoring
3. Problems to Solve
Key challenges addressed in this project:
- Integration: Synchronizing configurations across frontend, backend, and infrastructure
- Security: Preventing credential leaks, controlling API access, minimizing unnecessary public exposure
- Operations: Monitoring logs and system health to detect issues early
- Scalability: Ensuring system performance under increasing user load
4. Solution Architecture
4.1 Idea and Objectives
Context and Problem
The system is designed to manage personal health and workout planning.
System Capabilities:
- Manage user profiles and authentication data
- Track body metrics and calculate health indicators
- Manage workout plans, sessions, and logs
- Manage nutrition data by meal and by day
Target Users:
- Individuals tracking health and fitness
Problems Addressed:
- Centralize health data in a single platform
- Reduce manual operations via APIs and real-time features
- Ensure deployability, operability, and scalability on AWS
AWS/FCAJ Use-case Alignment:
- A clear cloud-native use case leveraging AWS managed services
- Focused on secure, scalable, and monitored cloud deployment
Success Criteria
Expected Outcomes:
- Frontend delivered via CloudFront
- Backend APIs running on ECS Fargate
- Authentication via Cognito Hosted UI and JWT
- Centralized logging via CloudWatch
Success Metrics:
- Users can log in and access core APIs
- Core flows (workout, health metrics, nutrition) work end-to-end
- ECS service rollout completes successfully and remains stable
- Issues can be quickly traced via logs and health checks
4.2 System Architecture:

4.3 Main Data Flow:
- Authentication Layer: Mobile app connects directly to Amazon Cognito for identity and login management.
- Access & Distribution Layer: Requests go through Route 53 (DNS) to CloudFront (CDN). CloudFront serves frontend from S3 or routes API requests to ALB.
- Backend Processing Layer: ALB balances traffic and forwards requests to Spring Boot containers on ECS Fargate. ECS pulls images from ECR and retrieves secrets from Secrets Manager.
- Data Layer: Fargate handles logic, interacts with RDS PostgreSQL and S3 Media Bucket. Amazon Bedrock is integrated as an AI chatbot.
4.4 AWS Services and Rationale:
Services Used:
- Amazon CloudFront – CDN for low latency and unified public endpoint
- Amazon S3 – Storage for static frontend and media files
- Application Load Balancer (ALB) – HTTP/HTTPS load balancing
- Amazon ECS Fargate – Managed container execution with auto scaling
- Amazon RDS PostgreSQL – Managed relational database
- Amazon Bedrock – AI chatbot integration
- Amazon Cognito – User authentication and identity management
- Amazon ECR – Container image registry
- Amazon CloudWatch – Centralized logging and monitoring
- AWS Route 53 & ACM – DNS and SSL/TLS certificate management
Why not Lambda/API Gateway:
- Backend is a Spring Boot monolith suited for container-based deployment
- Avoids complexity of serverless decomposition in early stages
- Speeds up delivery and simplifies operations
4.5 Security and IAM:
Principles:
- Least privilege for runtime roles
- No hard-coded credentials
- Minimize public exposure of data resources
Implementation:
- ECS Task Execution Role for image pulling and logging
- ECS Task Role limited to required S3 access
- Database credentials stored in Secrets Manager
- RDS deployed in private subnet
- ALB restricted to CloudFront traffic
- Backend validates Cognito access tokens
4.6 Scalability and Operations:
Scaling:
- ECS auto scaling based on CPU (min 2, max 4 tasks)
- Independent scaling for frontend and backend
Monitoring:
- CloudWatch Logs for containers
- RDS logs for query monitoring
- ALB health checks for instance status
4.7 CI/CD & IaC
To optimize operations and reduce manual errors:
5. Code Snippet
5.1 Dockerfile Backend

5.2 CDK Route API via CloudFront

5.3 Deploy Script

5.4 Stack Initialization

5.5 Application Screens

6. Estimated Cost
Region: us-east-1
| Category | Service | Configuration | Monthly Estimate |
|---|
| Frontend CDN | CloudFront | ~10GB | $1–5 |
| Storage | S3 | 2 buckets | $0.5–2 |
| Backend | ECS | 2 tasks | $15–20 |
| Database | RDS | t4g.micro | $30–35 |
| Registry | ECR | 1GB | $0.1–1 |
| Logging | CloudWatch | logs | $5–15 |
| Secrets | Secrets Manager | 2 secrets | ~$1 |
| Load Balancer | ALB | 1 ALB | $18–22 |
| Auth | Cognito | free tier | $0 |
| DNS + SSL | Route53 + ACM | | $0.5–1 |
Total: ~$71–100/month
Notes:
- No NAT Gateway → saves ~$32/month
- Actual cost depends on traffic and usage
7. Risks and Mitigation
| Risk | Impact | Priority | Mitigation |
|---|
| Sensitive data exposure | High | P0 | Use Secrets Manager |
| Wrong deploy path | Medium-High | P0 | Pre-check scripts |
| OAuth mismatch | High | P0 | Sync environments |
| Health check inconsistency | Medium | P1 | Standardize endpoint |
| Cost increase | Medium | P1 | Budget alerts |