freelancer for app refactoring and cleanup mern stack developer web programming react wasm integration dotnet developer freelancer for headless ecommerce sites zustand react state library react query data fetching react development responsive web design react lazy loading components website performance optimization react memoization optimization php development react native reanimated https://software-developers-for-h78876.tokka-blog.com/39790048/the-greatest-guide-to-nextjs-with-supabase-backend