Creative Front-End Developer for Cinematic, Interactive Web Quiz (With Analytics & Modular Code)

I'm building a premium interactive web experience that combines cinematic video, continuous music, and quiz mechanics to create an experience that feels closer to a game than a traditional website. The visual assets, music, quiz content, and product vision already exist. What I need is an experienced engineer who can build the underlying architecture correctly from the beginning. My top priorities are: * A maintainable codebase that future developers can easily understand and extend. * Clean separation between video playback, audio playback, quiz logic, UI, analytics, and payments. * Excellent performance on mobile and desktop. * Scalability for future features. The application should support: * Cinematic transitions between scenes. * Background music that continues seamlessly while users take as much time as they need answering questions. * Interactive question overlays. * Tracking user answers and determining personalized results. * Payment (Stripe) integration after quiz completion. * Automated PDF and PNG delivery. * Robust analytics. Analytics are extremely important. I want to understand things like: * How many users start the quiz. * How long users spend on each question. * Where users drop off. * Quiz completion rate. * Purchase conversion rate. * Which questions perform best or worst. I'm **not committed to any particular framework or architecture.** If you believe React, Next.js, another frontend framework, or even a game engine would provide a better long-term solution, I'm interested in hearing your reasoning. When applying, please include: 1. Similar projects you've built. 2. How you would architect this application. 3. Why you would choose that architecture. 4. How you would ensure the project remains maintainable for future developers.