Senior Python/FastAPI Engineer to Complete AI Video Backend

We are looking for a Senior Python/FastAPI Backend Engineer to complete the video-generation backend of an existing AI SaaS platform. This is AI-powered platform that allows users to generate short-form videos for TikTok, YouTube Shorts, and Reels. The website, infrastructure, authentication, user dashboard, admin dashboard, settings, credits system, payment gateway, AWS storage, and most core systems are already built. This project is not a new backend build. The task is to understand the existing codebase and complete the remaining video-generation features. This is not a project from scratch. Scope There are three video-generation niches: - Paper Quiz: Approximately 90% complete and already generates videos, but needs final fixes, testing, and stability improvements. - Quiz Video: Approximately 60% complete. The frontend is ready, and many features are shared with Paper Quiz. - Would You Rather: The frontend is ready, but the backend generation workflow must be built. Each niche also includes: - Step-by-Step video creation. - One-Click AI video generation. The selected engineer will complete these workflows, integrate them with the existing frontend, reuse shared backend services, and improve reliability. Technical Stack - Python and FastAPI - PostgreSQL, SQLAlchemy, and Alembic - Celery and Redis - FFmpeg and media processing - AWS S3 and CloudFront - External AI APIs Do not apply if your experience is limited to standard websites or CRUD APIs.