Web/Mobile App Upgrade and Maintenance

I am looking for a skilled developer to upgrade and maintain my web/mobile app.

Preferred Technology Stack:
Flutter
PHP
Laravel
Python
Html

Specific Upgrades Needed:
- Bug Fixes: I need someone who can identify and fix any bugs in the app.
- Integration with third-party services
- Performance optimization
- Experience with the preferred technology stack

If you have the necessary skills and experience, please submit your proposal.