Freelance Full-Stack Web App Developer

About the Role

This is a freelance role for the 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, ranging 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 support these products.

Responsibilities

• Build interactive web applications using frontend frameworks (React, Next.js, Vue, or similar) and backend APIs (Python/FastAPI/Flask or Node/Express).
• Design and implement data models, schemas, and persistence layers using SQL (PostgreSQL, SQLite) or NoSQL databases.
• Implement authentication, sessions, and basic role-based access control.
• Integrate third-party APIs and AI/LLM services (OpenAI, Anthropic, or similar) into product features.
• Manage state, handle user input validation, error states, and loading states effectively.
• Develop standalone Python tools and scripts for data processing, API clients, and backend utilities.
• Review, debug, optimize, and refactor full-stack applications to improve correctness, security, performance, and maintainability.
• Write clear, testable code and troubleshoot end-to-end issues across frontend, backend, and database layers.

Qualifications

• At least 3 years of relevant experience in full-stack web development or shipping interactive web applications (required).
• Bachelor's or Master's Degree in Computer Science, Engineering, Information Technology, or related technical fields is a plus.

Skills

• Strong command of JavaScript/TypeScript and proficiency in at least one modern frontend framework (React, Next.js, Vue, Svelte, or similar).
• Solid backend experience in Python (FastAPI, Flask, Django) and/or Node.js (Express, NestJS).
• Hands-on experience with relational databases (PostgreSQL, MySQL, SQLite) and basic schema design.
• Experience implementing REST APIs, request validation, error handling, and authentication flows.
• Familiarity with deployment platforms (Vercel, Netlify, Render, Railway, or similar).
• Experience integrating LLM APIs or other AI services into product features is a strong plus.
• Proficiency with version control (Git) and basic testing practices.

Additional Requirements

• Strong attention to detail and commitment to building robust, production-ready products.
• Self-directed work ethic with the ability to architect, build, and ship features independently.
• Portfolio of shipped web applications (required).
• English proficiency: Upper-intermediate (B2) or above (required).

Schedule

Tasks are estimated to require around 10–20 hours per week during active project phases. This is an estimate and not a guaranteed workload, applicable only while the project is active.

Pay

Contributors can earn up to $30 per hour, depending on their level and pace of contribution. Compensation varies across projects based on scope, complexity, and required expertise.

Benefits

• Work fully remote on your own schedule with just a laptop and stable internet connection.
• Apply your expertise to real-world technology projects and gain experience building high-quality solutions for a global platform.
• Participate in performance-based bonus programs that reward high-quality work and consistent delivery.