Summary FastAPI Backend Developer, Flask Migration Focus About Us Mandarin Blueprint is an immersive Chinese language learning platform and community. Our mission is to help learners make significant progress in Mandarin fluency using our innovative and proven methods. We are seeking a highly skilled, bilingual (English/Mandarin) Backend Developer to lead a critical framework migration. Our Core Values: At Mandarin Blueprint, our culture is built on shared values that guide how we work, learn, and grow together: Heartfelt Dedication: To our members. To our team. To your career. We take time to teach others, share knowledge, and give birth to wisdom. Help First: We lead with value before receiving it. We simplify the work of our team members by removing constraints and obstacles, and we find joy in solving problems for Chinese learners and teammates alike. Humble Confidence: No arrogance. Know your stuff. Be open and vulnerable—no one is perfect. We actively pursue knowledge and continuous learning to improve our lives and careers. Do What You Say: We fully deliver on what we commit to. We know ourselves and our limits, take responsibility, and blame no one. We finish what we start. Role Overview As a key member of the MB Elite development team, you will lead the migration of an existing Mandarin learning web application from Flask to FastAPI. Your main responsibility is to ensure a smooth framework transition while preserving full feature parity, performance, and reliability. You will work deeply on backend architecture, converting Flask blueprints into FastAPI routers, modernizing authentication flows, and maintaining a stable REST API layer. The platform relies on Supabase (PostgreSQL) for data storage, includes JWT based authentication, course and content management, spaced repetition learning logic, chatbot features using OpenAI, and progressive web app capabilities. The ideal candidate is a hands-on Python developer with strong FastAPI experience, confidence reading Flask codebases, and a careful, methodical approach to migrations. You should be comfortable working independently, communicating clearly in a remote environment, and writing clean, maintainable code as the system evolves. This role offers the opportunity to own a meaningful backend modernization project for a learning platform, and to help shape future development after the migration is complete. Responsibilities – Migrate the current Flask backend to FastAPI as the primary deliverable. – Convert Flask blueprints into FastAPI routers and reorganize the backend structure cleanly. – Maintain and enhance backend functionality during and after migration. – Migrate session based authentication to FastAPI compatible flows. – Design, develop, and maintain RESTful API endpoints for both public and authenticated users. – Implement and secure JWT authentication, authorization, and session management. – Work with Supabase (PostgreSQL) for database queries, schema handling, and performance. – Integrate third party APIs, including OpenAI for chatbot features. – Ensure complete feature parity across all modules, including: User authentication and registration Invitation code management Course and content management Character and sentence learning modules Review system and spaced repetition logic Account and settings management Public API endpoints PWA related backend support – Debug, test, and fix issues across the application. – Write clean, maintainable, scalable code following best practices. Must-Have Qualifications – Language Proficiency: Native or professional fluency in English and Mandarin Chinese (HSK 5 or 6 certification required). – Strong hands-on experience with FastAPI, including production level use. – Solid working knowledge of Flask to interpret and migrate the existing codebase. – Strong Python skills (3.9+), including async and modern backend patterns. – Proven experience designing and maintaining REST APIs. – Prior experience migrating Flask to FastAPI or similar backend migrations. – Experience with Supabase or PostgreSQL based backends. – Practical knowledge of JWT auth and secure session handling. – Familiarity with Git workflows and version control. – Strong debugging ability, attention to detail, and backend security awareness. Nice-to-Have Qualifications (Preferred Skills) – Experience building or supporting PWAs. – OpenAI API integration experience. – Familiarity with spaced repetition systems, learning algorithms, or EdTech apps. – Comfort working with Jinja2 templating and TailwindCSS. – Experience with Gunicorn deployments and production tuning. – Strong async and await understanding in Python, performance tuning in FastAPI. Compensation Structure – Hourly Rate: USD $25–$40 per hour, depending on experience and skill level. – Working Hours: Approximately 30 to 40 hours per week. – Time Zone Overlap: Candidates must have at least 3 to 4 hours of daily overlap with China Standard Time (UTC+8) to enable effective collaboration