Change the World, Bit by ByteAt 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 RoleAs 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 DoBuild & 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 AreExperienced: 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 essential.Tech Versatile & Secure: You go beyond just writing features.Strong Backend & Frontend skills (Python/Django and React preferred, but we value solid engineering fundamentals).Infrastructure Mastery: You have strong knowledge of cloud infrastructure (AWS), DevOps, and deployment pipelines.Security First: You understand OWASP top 10, data encryption, and secure authentication practices. You build systems that protect user data.AI/LLM Proficiency: Experience with AI coding tools and techniques for integrating LLMs into the development process is highly desirable.Problem Solver: You care about solving the problem rather than just using the flashiest new tool. You understand how to build lean and efficient solutions.Nice to Have (But Not Required)Language Skills: Proficiency in Spanish or other UN official languages is a great asset.Accessibility Expert: You know how to build inclusive web experiences that meet WCAG standards.Sustainable Tech: You have knowledge or interest in "Green IT" and sustainable hosting practices to minimise carbon footprint.Why Apply?Meaningful Work: Your code will directly support impactful projects in sectors that change lives.Global Mindset: Work with a diverse, international team and partners worldwide.Senior Impact: At your level, your voice matters. You will help shape technical strategy and team culture.Remote/Flexible Culture: We focus on output and impact rather than hours in a chair.Ready to join us in changing the world, bit by byte? Click Easy Apply today.(Note: A minimum of 8 years of software development experience is required for this senior role.)