Specific delivery app for both android and ios

I'm in need of a senior React Native developer to handle the implementation of user authentication and push notifications in my upcoming mobile application. The app is going to be a cross-platform app, supporting both iOS and Android.

The priority of the job is ensuring the user experience is smooth and secure. This means that the authentication process should be robust and user-friendly. In addition, push notifications are an essential feature that needs to be seamlessly integrated into the app.

Key Responsibilities:
- Develop user authentication flow, ensuring it's secure and intuitive
- Implement push notifications across the application
- Ensure the app is optimized for both iOS and Android

As I do not have existing UI/UX designs, I would appreciate some assistance or ideas regarding the overall design and layout of the app. If you have experience in this area, it would be a plus.

Ideal candidates should have:
- Proven experience in developing React Native applications
- Experience in implementing user authentication and push notifications
- Strong understanding of mobile platforms and best practices
- Ability to work collaboratively on design aspects
- Excellent communication skills, both technical and non-technical