Research: React Native + React selected for mobile and web

- Completed mobile-first platform strategy research
- React Native selected for iOS and Android mobile apps
- React selected for web companion app
- 70-80% code sharing between mobile and web
- Excellent health sensor integration (HealthKit, Health Connect)
- QR scanning, encryption, and background sync support
- Created comprehensive frontend research documentation
- Updated README with platform strategy
- Updated tech stack decisions

Key advantages:
- Single language (TypeScript) reduces development cost
- 70-80% code sharing between mobile and web
- Excellent health sensor integration
- Great chart visualization for web companion
- Faster time to market

Next: State management research (Redux vs Zustand)

thoughts/research/2026-02-14-tech-stack-decision.md

@@ -7,7 +7,6 @@
 ## Decisions Made
 
 ### 1. Rust Web Framework: Axum
-
 **Decision**: Axum 0.7.x
 
 **Rationale**:
@@ -17,30 +16,87 @@
 - Tower middleware ecosystem
 - Excellent async patterns for lazy loading
 
-**Risk Mitigation**:
-- Pre-1.0 API is stable enough for production
-- Strong backward compatibility maintained
-- Many production deployments exist
-
 **Reference**: [2026-02-14-performance-findings.md](./2026-02-14-performance-findings.md)
 
 ---
 
+### 2. Mobile Framework: React Native
+**Decision**: React Native 0.73+ for iOS + Android
+
+**Platform Strategy**:
+- **Primary**: Mobile apps (iOS + Android) - Daily health tracking, sensor integration
+- **Secondary**: Web browser - Extensive reporting, visualization, profile management
+
+**Rationale**:
+- **70-80% code sharing** between mobile and web (single language: TypeScript)
+- **Health sensor integration**: react-native-health (HealthKit), react-native-google-fit (Health Connect)
+- **QR code scanning**: react-native-camera
+- **Encryption**: react-native-quick-crypto (AES-256-GCM, PBKDF2)
+- **Web charts**: Recharts for React (beautiful visualizations)
+- **Team skills**: Single language (JavaScript/TypeScript) reduces development cost
+- **Time to market**: Faster than native or Flutter
+
+**Reference**: [2026-02-14-frontend-mobile-research.md](./2026-02-14-frontend-mobile-research.md)
+
+---
+
+### 3. Web Framework: React
+**Decision**: React 18+ for web companion app
+
+**Rationale**:
+- **70-80% code sharing** with React Native (business logic, state, API, encryption)
+- **Charts**: Recharts for beautiful health data visualizations
+- **Ecosystem**: Largest npm ecosystem
+- **Team skills**: Single language (TypeScript)
+
+---
+
+## Technology Stack Summary
+
+### Backend
+- **Framework**: Axum 0.7.x
+- **Runtime**: Tokio 1.x
+- **Middleware**: Tower, Tower-HTTP
+- **Database**: MongoDB (with zero-knowledge encryption)
+- **Language**: Rust
+
+### Mobile (iOS + Android)
+- **Framework**: React Native 0.73+
+- **Language**: TypeScript
+- **Health Sensors**: react-native-health, react-native-google-fit
+- **Encryption**: react-native-quick-crypto
+- **HTTP**: Axios
+
+### Web
+- **Framework**: React 18+
+- **Language**: TypeScript
+- **Charts**: Recharts
+- **HTTP**: Axios
+
+### Shared (Monorepo)
+- **Language**: TypeScript
+- **State**: Redux/Zustand (TBD)
+- **API**: Axios
+- **Encryption**: AES-256-GCM, PBKDF2
+- **Validation**: Zod
+- **Date**: date-fns
+
+---
+
 ## Still To Be Decided
 
-### 1. Frontend Framework (Priority: High)
+### 1. State Management (Priority: High)
 
 **Options**:
-- React (most popular, largest ecosystem)
-- Vue.js (simpler learning curve)
-- Svelte/SvelteKit (modern, compiled, smaller bundles)
+- Redux (mature, large ecosystem)
+- Zustand (simple, modern)
+- Jotai (atomic, minimal)
 
 **Considerations for Normogen**:
-- Client-side encryption requirements
-- Chart/visualization libraries
-- Mobile app code sharing
-- Zero-knowledge architecture
-- Real-time data updates
+- 70-80% code sharing between mobile and web
+- Complex state (family structure, multi-person profiles)
+- Offline synchronization
+- Encrypted data caching
 
 ---
 
@@ -54,13 +110,47 @@
 **Considerations for Normogen**:
 - Zero-knowledge password recovery
 - Token revocation strategy
+- Multi-factor authentication (future)
 - Integration with client-side encryption keys
 - Family member access control
 
 ---
 
+### 3. Database Schema (Priority: High)
+
+**Collections to Design**:
+- Users (authentication, profiles)
+- Families (family structure)
+- Health Data (encrypted health records)
+- Lab Results (encrypted lab data)
+- Medications (encrypted medication data)
+- Appointments (encrypted appointment data)
+- Shared Links (time-limited access tokens)
+
+---
+
+## Recommended Order
+
+1. Rust Framework: Axum (COMPLETED)
+2. Mobile/Web Framework: React Native + React (COMPLETED)
+3. State Management: Redux vs Zustand
+4. Authentication: JWT with recovery phrase
+5. Database Schema: Design MongoDB collections
+6. Create POC: Health sensor integration test
+7. Implement Core Features: Authentication, encryption, CRUD
+
+---
+
 ## Next Research Priority
 
-Research frontend framework options for zero-knowledge encrypted health data platform.
+**Research Question**: Which state management library (Redux vs Zustand) is best for Normogen's encrypted health data platform?
 
-Estimated Research Time: 3-4 hours
+**Considerations**:
+- 70-80% code sharing between React Native and React
+- Complex state (family structure, multi-person profiles)
+- Offline synchronization
+- Encrypted data caching
+- TypeScript support
+- Bundle size (mobile)
+
+**Estimated Research Time**: 1-2 hours