Senior Fullstack Engineer (Node.js/AWS/AI-Native) - Portugal Full Remote

Senior Fullstack Engineer (Node.js/AWS/AI-Native) - Portugal Full Remote

ABOUT THE OPPORTUNITY

Are you an engineer who already builds with AI coding agents every day? We’re looking for an AI-native Senior Fullstack Engineer to own the design, build and scaling of production-grade software for a well-established UK digital retail and financial services company. AI tools are a core part of this role, not an occasional extra. You’ll use Claude Code, Cursor and similar agents to plan, build, test, debug and ship high-quality software quickly, and you’ll stay fully accountable for every line that goes to production.

PROJECT & CONTEXT

Our client is a recognised UK player in retail, payments, credit, fraud and financial services. The business is in the middle of a major technology transformation and is investing heavily in modern cloud platforms and AI-driven development.

You’ll work mainly with Node.js, TypeScript and AWS, building backend services and integrations across commercial platforms, payments, fraud, originations and financial infrastructure. Your work will cover:

• Designing and maintaining scalable, secure backend services and REST APIs
• Integrating third-party platforms and SaaS solutions
• Deploying, monitoring and scaling applications on AWS
• Reviewing and validating AI-generated code for security, performance and maintainability
• Refactoring and modernising existing services
• Building automated testing, CI/CD pipelines and observability
• Troubleshooting production issues

You’ll take requirements through to production with minimal supervision and work alongside technical and business stakeholders on UK business hours.

WHAT WE’RE LOOKING FOR (Required)

• Significant commercial experience in a senior, hands-on software engineering role
• Strong hands-on experience with Node.js, building and maintaining production-grade backend applications
• Strong proficiency in JavaScript and/or TypeScript
• Practical experience designing, deploying and maintaining applications on AWS
• Solid backend engineering skills, including API development, system integration and software architecture
• Experience with databases, data modelling, automated testing, CI/CD and Git
• AI-native development workflow, with daily use of Claude Code, Cursor, GitHub Copilot or similar tools
• Experience using AI agents across the whole SDLC: planning, implementation, debugging, refactoring, testing and delivery
• Ability to review, debug and secure code, including AI-generated code
• Proven ability to work independently, own delivery and make sound technical decisions
• Availability to work UK business hours
• Languages: Fluent English, written and spoken (mandatory)

NICE TO HAVE (Preferred)

• Experience in fintech, payments, fraud, credit or other regulated environments
• Experience integrating third-party SaaS platforms and external APIs
• Experience with cloud-native architectures, distributed systems and production operations

Compensation: €2,600 – €3,500/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