Change the World, Bit by Byte

At T4G Lab, we are more than just a tech consultancy. We are partners in impact. We build technology that matters. We work with startups, non-profits, universities and United Nations to solve real-world problems in Health, Climate Change, Education, Research or Financial Access. We are looking for a seasoned Full Stack Engineer with deep experience to join our global team. You will build scalable, high-impact solutions that empower organisations to move faster and do more good.

The Role

As a Senior Member of our engineering team, you will be hands-on in designing, building, and deploying robust applications. You won't just be writing code. You will be crafting solutions for complex challenges, ensuring our partners get world-class, secure, and sustainable products. This is a pure Full Stack role where you will own features from the database to the UI, but with a heavy emphasis on architectural soundness and infrastructure security.

What You’ll Do
- Build & Scale: Develop high-quality, maintainable software across the full stack (Frontend + Backend).




- Secure Infrastructure: Take ownership of cloud architecture. You will ensure our systems are not just functional but are secure by design and optimised for performance.
- Impactful Work: Work on diverse projects ranging from AI integration to lean product adjustments for startups and non-profits.
- Mentor & Lead: Use your experience to set coding standards and mentor other developers in the team.
- Collaborate: Work directly with founders, product managers, and non-technical stakeholders to translate "vision" into "shipped code."

Who You Are
- Experienced: You have 8+ years of professional experience in software engineering. You have seen it all, including legacy code, greenfield projects, and complex migrations.
- Fluent in English: You have excellent written and verbal communication skills in English. As a integral consultancy, clear communication with international partners is es

📌 Senior Full Stack Engineer (Barcelona)
🏢 T4G Lab
📍 Barcelona