I need an APP developer to work on my app to fix the coding

Description

I seek a skilled mobile application developer to refine an existing product and optimize it for future fundraising efforts. The propriety app requires updates to its underlying architecture and codebase to resolve existing errors and vulnerabilities while ensuring alignment with current technical standards. Specifically, capabilities must be enhanced, performance optimized and usability improved through rigorous testing prior to pivotal presentations seeking financial backing. Experience with similar programming challenges and a proven track record of successfully guiding projects from inception to completion within stipulated timeframes and budgets is essential. Proficiency in the app's platform(s) and programming language(s) is mandatory. The selected candidate will be granted access to source code and work closely with myself to understand core functionality, pinpoint areas for improvement and implement solutions iteratively per an agreed-upon statement of work. References and portfolio highlighting past successful projects of this nature will be appreciated.