Senior Full-Stack Developer Needed to Audit, Complete & Productionise Existing Platform (90% Built)

I have an existing web and mobile application that is approximately 85–90% complete and has been under active development for a significant period of time. The core architecture, database, user flows, mobile app, admin functionality, and payment systems are already built. The project is now at the stage where it requires an experienced developer to thoroughly review the codebase, identify remaining issues, complete unfinished areas, improve overall quality, and help prepare the product for launch. I am not looking for someone to build an app from scratch. I am looking for someone who can confidently take ownership of an existing codebase, quickly understand how it works, and help get it across the finish line. What I Need Phase 1: Technical Audit * Review the entire codebase * Identify bugs, weaknesses, and incomplete functionality * Assess architecture, scalability, and maintainability * Produce a clear action plan with priorities Phase 2: Completion & Improvement * Resolve outstanding bugs * Complete unfinished features * Improve reliability and user experience * Refactor problematic areas where necessary * Improve overall code quality Phase 3: Launch Preparation * Production readiness review * Performance optimisation * Security review * Mobile testing and fixes * Deployment support * App Store and Play Store readiness