Senior Fullstack AI Applied Engineer (React/Node.js) - Remote Portugal

TITLE: Senior Fullstack AI Applied Engineer (React/Node.js) - Remote Portugal ABOUT THE OPPORTUNITY We're looking for a Senior Fullstack AI Applied Engineer to join a well-established, engineering-driven software consultancy that builds software designed to improve lives. This role sits at the intersection of strong software engineering fundamentals and modern AI-assisted development — you'll combine hands-on fullstack delivery with agentic workflows and AI coding tools to ship high-quality software faster. You'll work closely with product, design, and engineering teams, helping shape how AI-enabled practices evolve across projects, while mentoring others on the effective and responsible use of AI throughout the development lifecycle. PROJECT & CONTEXT You'll design, build, and maintain modern web applications spanning frontend and backend systems, contributing to architectural decisions and ensuring solutions meet performance, security, reliability, and maintainability standards. A core part of the role involves integrating AI coding assistants (such as Claude Code, GitHub Copilot, Cursor, or OpenAI Codex) into daily workflows — using them for design, implementation, testing, debugging, refactoring, and documentation. You'll also build guardrails and validation mechanisms (automated testing, specification conformance checks, evaluation frameworks) to ensure AI-generated code meets production-readiness standards, and contribute to the team's broader engineering practices for agentic software development. WHAT WE'RE LOOKING FOR (Required) 5+ years of professional software engineering experience Relevant experience with React and Node.js Strong track record delivering software across the full Software Development Life Cycle Experience building production-grade software applications Experience working within Agile product development teams Demonstrated experience using AI coding assistants (e.g., GitHub Copilot, Cursor, Claude Code, or equivalent) in professional development work Experience using AI for code generation, refactoring, debugging, testing, documentation, and software design Familiarity with agentic development workflows and AI-powered engineering tools Experience creating and maintaining prompts, workflows, skills, or agent instructions as reusable engineering assets Ability to critically evaluate and validate AI-generated outputs Understanding of validation techniques for AI-assisted development, including testing, specification-based verification, and human-in-the-loop review Strong communication and technical collaboration skills Fluent in English (required) NICE TO HAVE (Preferred) Experience designing workflows or frameworks specifically to improve trust/confidence in AI-generated outputs Experience working with AI agents to execute multi-step development activities Prior experience mentoring engineers on AI-assisted development practices Compensation: €2,300 – €2,900/month net, depending on experience and seniority level. Why HumanIT people stay (4.4 Glassdoor, 89% recommend) - 15th month salary - Health insurance covering your family - Birthday off - Mobility program for digital nomads - Real work-life balance Full benefits https://www.humanit.pt/careers/#perks What it's really like https://www.humanit.pt/careers/#work-at