Forge Fitness: Biometric & Workout Analytics

Forge Fitness is an Android application built for athletes and fitness enthusiasts who require granular workout telemetry, real-time heart rate zone tracking, and automated Google Health Connect synchronization.

🎯 Architecture & Engineering Focus

To handle incoming sensor data streams (step counters, accelerometer, and Bluetooth Low Energy heart rate monitors) without depleting battery life or blocking the main thread, the app was built from the ground up with Clean Architecture:

app/
 ├── data/
 │    ├── datasource/ (BleSensorManager, HealthConnectClient, Room)
 │    └── repository/ (WorkoutRepositoryImpl, BiometricsRepositoryImpl)
 ├── domain/
 │    ├── model/ (WorkoutSession, HeartRateZone, UserProfile)
 │    └── usecase/ (CalculateCaloricBurnUseCase, SyncHealthDataUseCase)
 └── presentation/
      ├── dashboard/ (DashboardViewModel, DashboardScreen)
      ├── liveworkout/ (LiveWorkoutService, LiveWorkoutScreen)
      └── designsystem/ (ForgeTheme, BiometricGauges, PulseLineChart)

💡 Key Engineering Accomplishments

1. Android Health Connect Integration: Read and wrote biometric records across Samsung Health, Google Fit, and Garmin seamlessly with user privacy consent handling.
2. Foreground Service with Notification Telemetry: Maintained a sticky foreground service during active sessions with real-time notification actions (Pause, Resume, Finish) and MediaStyle formatting.
3. Custom Canvas Charting in Jetpack Compose: Developed hardware-accelerated bezier curve graphs that smoothly animate 10,000+ heart rate data points using drawWithCache and Canvas path clipping.
4. Resilient Background Syncing: Utilized WorkManager with exponential backoff and network constraints to upload telemetry batch payloads to backend servers.

🔬 Unit & UI Testing Strategy

• Domain UseCases: 100% test coverage using MockK and JUnit 5.
• Flow & Coroutines Testing: Used Turbine for testing cold flows, debounce triggers, and state transitions in ViewModel.
• Screenshot Regression: Automated Compose screenshot tests with Paparazzi on CI pull requests.