Hello.
I appreciate your job posting and I'm really confident for your job since I'm Cross Platform Developer.
As I've worked on mobile development for several years, I have rich experience in Cross Platform development like React Native, Ionic, Flutter and so on.
For backend, I use AWS Amplify which is good for providing lot of services. The authentications including Google Auth and Apple ID auth can be implemented by Cognito and OAuth2.
And for DB, I used NoSQL - DynamoDB which is provided by AWS Amplify.
Besides this experience, I've done Mobile Backend jobs with Firebase, and MySQL too.
I work enthusiastically when I work for fixed budget project- more than 14 hours a day, to deliver the result asap for the client.
I have Native-like English, so communication is no longer the problem between us.
If you're interested in me, contact me anytime, I'm always here for your response.
Best regards.