GCP Developer for Video-to-MP3 (128kbps) API with Webhook (Large Files)

PROJECT OVERVIEW We are looking for an Google Cloud Platform (GCP) developer to build a serverless API workflow. The system will receive a Google Drive File ID of a video, convert it to a 128 kbps MP3, save it to a specific Google Drive folder which is always the same, and trigger a webhook upon completion. CRITICAL REQUIREMENT: VERY LARGE FILES The system MUST be able to reliably process multi-gigabyte video files (e.g., 5GB to 10GB+) without running into memory limits, disk space errors, or request timeouts. The architecture must be designed to handle large file streams or provide adequate temporary storage. WORKFLOW & TECHNICAL REQUIREMENTS 1. Initial Request (Trigger): An unauthenticated HTTP POST call is made to the endpoint. The payload will contain: - file_id: The Google Drive ID of the source video file. - job_id: A custom string to track the job. - webhook_url: The URL that the system needs to call when the conversion is finished. 2. Background Processing: Because large files take a long time to convert, the endpoint should accept the request and process the file asynchronously to avoid HTTP timeouts. - The system accesses the video file via the Google Drive API (using a Service Account). - It converts the video into a 128 kbps MP3 audio file. 3. Storage: - The generated MP3 file is uploaded to a predefined, standard Google Drive folder (the destination folder ID will remain constant). 4. Webhook Trigger: - Once the MP3 is successfully uploaded to Drive, the system sends a POST request to the provided webhook_url. - The webhook payload must include exactly these parameters: - job_id (passed from the initial request) - original_file_name (name of the original video) - original_file_id (Drive ID of the original video) - new_file_id (Drive ID of the newly created MP3) ENVIRONMENT & SIMPLICITY We want to keep this as simple and robust as possible. The solution will be deployed in our existing GCP project (shared environment). REQUIRED SKILLS - Google Cloud Platform (Cloud Run, IAM) - Python, Node.js, or Go - FFmpeg / Audio-Video Processing - Google Drive API