Key Responsibilities: 1. Build and maintain the mobile app using React Native (Expo) and TypeScript, and convert Figma designs into responsive UI 2. Develop core features such as onboarding, daily check-ins, AI food logging, partner sync, and step tracking 3. Take end-to-end ownership of features from planning to development, testing, and deployment 4. Develop backend logic using Firebase Cloud Functions and design scalable Firestore database structures 5. Build APIs and integrate Firebase services (Auth, Firestore, Cloud Functions) seamlessly with the mobile app 6. Integrate third-party services including OpenAI APIs, RevenueCat (subscriptions), Mixpanel (analytics), and Sentry (error monitoring) 7. Write clean, scalable code, manage state (Zustand or similar), and handle debugging, testing, and performance optimization 8. Collaborate closely with the founder, product, and design teams in a fast-paced, AI-native environment and maintain efficient Git workflows