Senior Fullstack Developer for Global Interactive Cinematic Music Experience

We are seeking a highly skilled Fullstack Developer to lead the initial phase of our 'Musical Kolossal Project', an ambitious interactive cinematic music experience launching in 13 countries. This project requires a developer with deep technical expertise, particularly in video handling, performance optimization, and robust backend development for content management. We are not looking for a generic developer; we need someone who can excel in the following three critical areas:

1. Fullscreen Video Playback on iPhone and PC:
  The primary requirement is to implement flawless fullscreen video playback across both iPhone and PC platforms. This includes ensuring a clean, cinematic start without standard YouTube controls, and enabling audio unmute on the first user tap. The solution must be robust and visually seamless, avoiding any broken or glitchy appearances.

2. Instant Loading for 20x 15-Second Videos on 4G:
  You must implement advanced techniques for loading approximately twenty 15-second videos instantly, even on 4G networks. This necessitates expertise in lazy loading, smart preloading strategies, and HLS/MP4 optimization. Simply compressing videos is not an acceptable solution.

3. Admin Panel for Video Uploads Without Code Interaction:
  Develop an intuitive admin panel that allows non-technical users to upload MP4 videos and assign them to specific regions (e.g., 'Italy') without needing to touch any code. This requires proficiency with cloud storage solutions like S3/Cloudinary, a simple yet powerful api, and json configuration. Solutions involving ftp and manual html editing are not suitable.

Project Scope:
This initial phase, 'V1 Global Launch', targets 5 tracks per region across eu, usa, china, and japan, totaling 20 tracks. The goal is to prove the concept globally.

Selection Process:
1. Candidates must provide concise, technical answers (max 10 lines) to the three questions outlined above.
2. Successful candidates will proceed to a paid test task: $250 for Card 1 - a 15-second intro with rotating light animation, with a 48-hour deadline.
3. Successful completion of the test task will lead to a long-term collaboration for all 20 Musicals.

Do NOT apply if:
- You have no prior experience working with video on mobile devices.
- Your technical expertise is limited to generic 'MERN stack' knowledge.
- You require extensive calls to understand project requirements.

Apply if:
- You possess clear, actionable technical knowledge and can demonstrate how to achieve the project goals.
- You have a proven track record of building websites with heavy interactive video content.