Freelance Full-Stack Web App Developer

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.

- 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 correctness, security, performance, and maintainability. - Write clear, testable code and debug end-to-end issues across frontend, backend, and database.

- 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.

Candidates should have a strong foundation in full-stack web development, modern frontend frameworks, backend architecture, and building interactive browser-based applications end-to-end. We are looking for specialists who can confidently work across frontend, backend, databases, and APIs, design robust application logic, and build production-ready web applications.

Strong problem-solving skills, attention to detail, and the ability to independently architect and ship complete features are essential.

- Strong command of JavaScript/TypeScript and 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, Fly.io , Railway, or similar). - Experience integrating LLM APIs or other AI services into product features is a strong plus. - Comfortable with version control (Git) and basic testing practices.

- Strong attention to detail and commitment to building working, robust products - not demos. - 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).

Why this freelance opportunity might be a great fit for you?

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

Mindrift is looking for skilled Full-Stack Web App Developers (JavaScript/TypeScript + Python or Node) to join the Tendem project ( https://tendem.ai/ ) 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.

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.

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.

• 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 correctness, security, performance, and maintainability.
• Write clear, testable code and debug end-to-end issues across frontend, backend, and database.

• 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.

Candidates should have a strong foundation in full-stack web development, modern frontend frameworks, backend architecture, and building interactive browser-based applications end-to-end. We are looking for specialists who can confidently work across frontend, backend, databases, and APIs, design robust application logic, and build production-ready web applications.

Strong problem-solving skills, attention to detail, and the ability to independently architect and ship complete features are essential.

• Strong command of JavaScript/TypeScript and 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, Fly.io , Railway, or similar).
• Experience integrating LLM APIs or other AI services into product features is a strong plus.
• Comfortable with version control (Git) and basic testing practices.

• Strong attention to detail and commitment to building working, robust products — not demos.
• 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).

For this project, tasks are estimated to require around 10–20 hours per week during active phases, based on project requirements. This is an estimate, not a guaranteed workload, and applies only while the project is active.

On this project, contributors can earn up to $60 per hour equivalent , depending on their level and pace of contribution.

Why this freelance opportunity might be a great fit for you?

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