Full stack engineer

We are looking for a full stack engineer to join our Martian team. 100% Remote MarsBased is a boutique development consultancy based in Barcelona, focused on delivering high-quality, end-to-end web and mobile applications. We build solutions primarily using Ruby on Rails, React, and JavaScript, and strongly believe in remote work, clean code, and quality over quantity. We’re looking for a Full Stack Engineer with solid experience in Node.js, React, and Next.js to join our Martian crew. At MarsBased, you’ll work with a small, senior, and highly collaborative team that values autonomy, transparency, and craftsmanship. We care about doing things the right way, with clean architectures, thoughtful design, and deep, focused work (not endless meetings). If you love elegant code, solving real problems, and being part of a kind, experienced, and fully remote team, your next orbit might just be with us.

What you’ll do

• Build and maintain modern, scalable web applications using Node.js, React, and Next.js.
• Collaborate closely with clients and teammates in a friendly, remote-first environment.
• Contribute to architecture decisions and ensure clean, maintainable codebases.
• Use AI-assisted coding tools to improve development speed and quality.
• Help us refine our internal tools, workflows, and development culture.

General skills

• Clear and professional written and verbal communication with internal teams and clients/stakeholders.
• Enthusiastic and positive approach to new challenges; ability to quickly assimilate new information and processes.
• Ability to work independently, demonstrate strong self-management skills in a remote environment, and take ownership of projects.
• Excellent attention to detail and commitment to high-quality output.
• Proactive & able to work alone on projects managed by you.
• Fluency (written and spoken) in English and Spanish is required.
• Experience using AI agents or AI code editors (e.g., Cursor, Copilot) to assist in coding tasks.

Technical Skills

• 5+ years of production experience building Node and React applications.
• Production experience with Next.js, the App Router, and Server Components is required.
• Strong command of JavaScript and TypeScript.
• Solid understanding of relational databases and SQL.
• Experience with backend technologies like Ruby on Rails & Python is strongly valued.
• Experience with React Router or Remix is a plus.
• Production experience deploying and maintaining Node.js applications.
• Comfortable working with Docker and containers in both development and production environments.
• Experience with testing frameworks such as Jest or Cypress.
• Ability to write self-documented code. We expect you not only to solve problems but also to write code that is easy to understand.
• Ability to leverage AI coding assistants (e.g., GitHub Copilot, Gemini Code Assist,...