Full-Stack Developer Needed for Private Web-Based MP3 Streaming & Playlist Platform

We are looking for an experienced full-stack developer to build a private, web-based MP3 streaming and playlist platform for internal company use. This is not a Spotify clone or public streaming service. The scope is much more focused: we own and provide the MP3 media, users are company-authorized accounts, and playlists will be created and managed by administrators. The initial application will be hosted on our VPS and accessed through a web browser. We also intend to develop a Windows desktop client with controlled offline playback in a future phase, so the initial backend/API architecture must be designed with that expansion in mind. Core Version 1 Features The web application should include: * Secure user authentication * Administrator and standard user roles * One active playback session per user account * Admin ability to view and terminate active sessions * MP3 upload and library management * Track metadata management * Search by title and artist * Administrator-created playlists * Ability for one track to belong to multiple playlists * Browser-based MP3 player * Play/pause/next/previous controls * Shuffle mode that creates a randomized queue without repeating tracks until the playlist is exhausted * Persistent playback sessions/queues * Recent play history * Responsive interface for desktop, tablet, and mobile browsers * Secure media delivery with HTTP range request support * VPS/Docker deployment and HTTPS Configurable Audio Clips An important feature is the ability for an administrator to define optional start and end playback points for an MP3 without modifying the original file. For example, a full MP3 may be stored on the server, but the administrator could configure playback to begin at 00:48 and automatically end/advance at 01:48. The admin interface should provide a practical way to configure and preview these points. The underlying architecture should ideally allow this to expand later to multiple defined clips from a single master track. Single-Session Enforcement Each user account must be limited to one active playback session/device at a time. Users should not be able to use the same account simultaneously on multiple browsers or computers. Session enforcement must occur server-side. The architecture must also allow this restriction to eventually apply across both the web application and a future Windows desktop client. Administrators should be able to view and terminate active sessions. Future Desktop / Offline Capability The Windows desktop application and offline playback are NOT part of this initial development phase, but the Version 1 architecture must support adding them later without rebuilding the backend. Our future desktop application is expected to: * Use the same API and user accounts * Download authorized playlists/media for offline playback * Maintain an application-managed local media cache * Synchronize playlist changes and playback history * Restrict accounts to one active session/device * Use device-specific authorization * Require periodic online reauthorization Offline authorization will intentionally be short-lived—approximately 48–72 hours. After that period, the desktop application would need to reconnect to our server and renew authorization before offline playback could continue. We understand that absolute real-time session enforcement is impossible while a device is genuinely offline. We are looking for an architecture using short-lived, device-bound authorization that minimizes unauthorized simultaneous use. Technical Architecture We are open to the developer’s recommended technology stack. Possible technologies include: * Python/FastAPI or Node.js/TypeScript * JavaScript or a modern frontend framework * SQL database * Docker / Docker Compose * Linux/Ubuntu VPS * Nginx or Caddy * REST API We are specifically looking for someone who understands API architecture, authentication/session management, secure media delivery, databases, and production VPS deployment, rather than someone who can only build the front-end interface. Ownership & Documentation We require ownership/access to the completed project, including: * Complete source code * Frontend and backend source * Database schema/migrations * Docker/deployment configuration * API documentation * Deployment/restore instructions * Basic administrator documentation Development should use Git, and the completed project must be maintainable by another qualified developer if necessary. Any paid third-party services, APIs, libraries, or recurring costs must be disclosed before implementation. When Applying Please include: 1. Your proposed technology stack and why you recommend it. 2. Examples of relevant full-stack applications you have built. 3. Your experience deploying applications using Docker/Linux/VPS environments. 4. Any experience with HTML5 audio, media streaming, or HTTP range requests. 5. How you would implement the single-active-session requirement. 6. How you would structure the API/backend today so that a Windows desktop application with 48–72 hour offline authorization can be added later. 7. Your estimated development timeline. 8. Whether your proposal is fixed-price or based on estimated hours. Please do not simply send a generic proposal. We will provide a more detailed project specification/RFP to qualified candidates. Budget Our target budget for Version 1 is approximately $3,500–$6,000 USD, with $5,000 as the target project budget. We are willing to consider proposals outside this range when justified by experience, architecture, or additional value. We are prioritizing quality, maintainability, communication, and sound architecture over the lowest bid. The future Windows desktop/offline application will be a separate development phase.