Need a Flutter Developer (mobile-first). Must have experience with 3rd party API integrations + JSON data handling. Bonus: Worked with Fitbit/Oura/Garmin APIs. Platform Overview A mobile-only, web-based health analytics app (no native iOS/Android apps) that converts lab results and wearable data into a personalized Health Score with trend tracking and AI-generated insights. Patients will: • Upload their lab reports. • Connect wearables via the Terra aggregator. • See a daily-updated Health Score (including sleep). • Receive AI-generated summaries and 90-day health plans. • View progress by day, week, month, and year. Core Functional Features Mobile-Only Access • Detect desktop browsers → show QR code prompt to open on mobile. • Mobile web flow for all steps: registration, payment, device linking, viewing results. • Responsive vertical layout; no horizontal scroll. Lab Upload & Extraction • Users upload PDF lab reports directly from mobile. • OCR engine (Google Document AI or Textract) extracts lab values into JSON. • Parse key metrics: • A1c, Glucose, LDL, HDL, Triglycerides, Vitamin D, hs-CRP, TSH, Hematocrit. • Store values in structured form (lab_sets table). Health Score Engine • Calculates a composite score (0–100) with 5 sub-scores: • Metabolic (30%) • Cardiovascular (30%) • Inflammation (10%) • Hormone/Micronutrients (10%) • Lifestyle (20%) • Scoring thresholds editable via JSON config. • Sleep metrics from Terra are mandatory in Lifestyle sub-score. • Includes optional Styku adjustment (±5 points based on BF% trend). • Updates daily at 5 AM local time (cron job). Lifestyle Data Integration (via Terra) • Terra is the only aggregator. • Supports Fitbit, Oura, Garmin, Withings, Polar, and others via single mobile web connect. • User completes Terra’s hosted web flow to authorize. • Daily webhooks or scheduled pulls fetch: • Steps • Active minutes • Resting heart rate • HRV (RMSSD or similar) • Sleep duration and efficiency • Calories burned • Weight and body fat % • Store raw data → resample to daily/weekly/monthly aggregates. • Pull data every 24h automatically (cron/scheduler). Trends & Visualizations • Daily, weekly, monthly, and yearly trend charts for: • Steps, HR, HRV, Sleep, Calories, Weight, Body Fat %, Labs. • Charts show absolute values + 7-day moving averages. • Comparative arrows (↑/↓ vs last period). • Sleep and HRV data visually emphasized in daily dashboard. AI Summary & 90-Day Plan • Use OpenAI GPT-4o to generate: • Easy-to-read summary of lab + lifestyle results. • Personalized 90-day plan (nutrition + exercise + lifestyle). • AI prompt includes metrics only (no PHI). • Plan respects user preferences (exercise or food restrictions). Preferences & Customization • User-selectable limitations: • Exercise: e.g., “No running,” “Low time,” “Knee pain.” • Food: e.g., “No dairy,” “Low-FODMAP,” “Gluten-free.” • Stored in preferences table; filters AI recommendations. • Toggle to “Include Styku in Health Score.” Payments & Access • Stripe Checkout for: • Subscription (monthly). • One-time purchase (per lab upload). • Magic-link or SMS code for login (no passwords). • Stripe customer ID tied to anonymous user ID. Reports & Downloads • Generate 1-page PDF report (score, sub-scores, key trends, AI summary). • PDF view optimized for mobile and printable format.