Freelance Full-Stack Web App Developer

Mindrift is looking for skilled Full-Stack Web App Developers (JavaScript/TypeScript + Python or Node) to join the Tendem project () and build interactive browser-based applications for real-world use cases. In this role, you'll apply your full-stack engineering expertise to design, build, and maintain functional, robust, and user-friendly web applications. This part-time remote opportunity is ideal for professionals with hands-on experience in modern frontend frameworks, backend APIs, databases, and shipping interactive web products end-to-end. What We Do The Mindrift platform connects specialists with innovative technology projects. Our mission is to help develop high-quality AI technologies by combining real-world expertise from professionals across the globe with advanced AI development efforts. About the Role This is a freelance role for a Tendem project. As a Full-Stack Web App Developer, you'll design, build, and refine browser-based applications with real logic, state, persistence, and user input — from habit trackers and budgeting tools to internal dashboards, mini-SaaS tools, and AI-powered apps. You may also work on standalone Python applications and data-processing scripts that sit alongside or behind these products. Key Responsibilities Build interactive web applications with frontend (React, Next.js, Vue, or similar) and a backend API (Python/FastAPI/Flask or Node/Express). Design and implement data models, schemas, and persistence layers using SQL (PostgreSQL, SQLite) or NoSQL stores. Implement authentication, sessions, and basic role-based access where needed. Integrate third-party APIs and AI/LLM services (OpenAI, Anthropic, or similar) into product features. Handle state management, user input validation, error states, and loading states cleanly. Build standalone Python tools and scripts where required by the task (data processing, API clients, lightweight backend utilities). Review, debug, optimize, and refactor full-stack applications to improve