Form Factor

Founder & Lead Engineer · Sept 2025 – Present

A mobile fitness app that uses ARKit body tracking and Apple HealthKit to deliver real-time exercise form analysis, built from zero to shipped product.

The Problem

Most people working out alone have no reliable way to check their exercise form. Bad form leads to injury and stalled progress, but personal trainers are expensive and inaccessible. Existing fitness apps track reps and calories but ignore the quality of movement.

Role & Constraints

Founder & Lead Engineer

• Solo developer shipping across iOS client and backend
• Real-time CV processing on consumer mobile hardware
• Privacy-first approach to body/movement and health data
• Backend schema design for both current use and future ML pipeline

Approach

Built a mobile-first app using Expo and React Native that integrates Apple HealthKit to sync heart-rate, step, and body-composition data from Apple Watch into workout logs. Used ARKit body tracking to record joint and pose metrics for real-time form analysis. Designed backend schemas and structured logging in Supabase/Postgres to store health and pose data reliably and support debugging and future ML features.

Media

┌──────────────────────────────────────────────┐
│                 iOS Device                    │
│  ┌────────────┐ ┌───────────┐ ┌───────────┐ │
│  │ React      │ │ ARKit     │ │ Health    │ │
│  │ Native UI  │ │ Body      │ │ Kit       │ │
│  │ (Expo)     │ │ Tracking  │ │ Sync      │ │
│  └─────┬──────┘ └─────┬─────┘ └─────┬─────┘ │
│        └──────┬───────┘─────┬────────┘       │
└───────────────┼─────────────┼────────────────┘
          ┌─────▼─────┐ ┌─────▼─────┐
          │ Supabase  │ │ Pose &    │
          │ Auth +    │ │ Health    │
          │ Realtime  │ │ Data      │
          └─────┬─────┘ └─────┬─────┘
          ┌─────▼─────────────▼─────┐
          │   PostgreSQL             │
          │   Workout · Pose · Health│
          └─────────────────────────┘

Outcomes

• Shipped a working product with real-time form analysis via ARKit body tracking
• Integrated Apple HealthKit to sync watch data into workout logs
• Built end-to-end: mobile client, backend schemas, health data pipeline
• Maintained a steady release cadence as a solo developer

Proof

Reflection

Form Factor proved I can take a product from concept to shipping code on my own. The hardest part wasn't any single technology. It was making architectural decisions across mobile, backend, and health data with no team to delegate to. Every tradeoff was mine to own, from schema design for future ML features to privacy constraints on body tracking data.