Backend Ai Developer (Java/Quarkus) - Hybrid Leça Da Palmeira (2 Days/Week Office)

Humanit Digital Consulting; Viseu; On-site; EUR 40,000 - 65,000; Full time

Job summary

Humanit Digital Consulting is seeking a Mid-level Backend Developer to join their engineering team in the Iberian market. You'll design, build, and maintain backend services and APIs using Java and Quarkus, while embracing an AI-first approach to coding, testing, and reviews.

Day-to-day work includes features, bug fixes, refactors, API integrations, automated tests, and AI-assisted reviews. You will collaborate closely with backend engineers, QA, and product to deliver dependable, well-tested

Qualifications

• 4+ years of hands-on backend development experience.
• Proficient in Java with Quarkus familiarity.
• Daily use of AI-assisted development tools.
• Experience designing APIs and Java-based microservices.
• Experience writing automated unit and integration tests.
• Ability to translate business context into technical solutions.
• Curiosity to experiment with new AI tools.
• Comfort in a fast-moving AI-enabled environment.
• Strong attention to detail and problem solving.
• Good verbal and written English (minimum B1).
• Collaborative and able to manage multiple priorities.

Responsibilities

• Design, build, and maintain backend services and APIs using Java and Quarkus.
• Write automated unit and integration tests for backend systems.
• Contribute to AI-assisted code reviews and CI/CD troubleshooting.
• Collaborate with backend, QA, and product teams to deliver reliable software.
• Tackle features, bug fixes, and refactors in a fast-moving environment.

Skills

Backend development

Java

Quarkus

AI-assisted tools

API design

Microservices

Automated tests

CI/CD

Business context

Curiosity

Adaptability

English B1

Collaboration

Tools

GitHub Copilot

GitLab Duo

Claude Code

Quarkus

Job description

Our client, a technology-driven company shaping the future of mobility across the Iberian market, is looking for a Mid-level Backend Developer to join their engineering team. This is a chance to work at the intersection of backend engineering and applied AI, using tools like GitLab Duo and Claude Code as part of your everyday workflow to build reliable, high-quality software faster.

PROJECT & CONTEXT

You will design, build, and maintain backend services and APIs using Java and Quarkus, while embracing an AI-first approach to how the team codes, tests, and reviews software. Day-to-day work includes solving backend tasks such as features, bug fixes, refactors, and integrations, writing automated unit and integration tests, participating in AI-assisted and peer code reviews, and troubleshooting CI/CD pipelines with the help of GitLab Duo. You'll collaborate closely with backend engineers, QA, and product to deliver dependable, well-tested software in a fast-moving, AI-enabled environment.

WHAT WE'RE LOOKING FOR (Required)

• 4+ years of hands-on backend development experience
• Experience with Java (Quarkus is a plus)
• Practical experience using AI-assisted development tools such as GitHub Copilot, GitLab Duo, Claude Code, or similar as part of a daily engineering workflow
• Experience designing and building APIs and Java-based microservices that run reliably at scale in production
• Experience writing automated unit and integration tests for backend systems
• Ability to understand the functional and business context of a feature before designing the technical solution
• Curiosity and willingness to experiment with new AI tools and integrate them responsibly into day-to-day development practices
• Comfortable working in a fast-moving environment where AI-assisted development practices are still evolving
• Strong attention to detail, critical thinking, and problem-solving skills
• B1 English (Intermediate) minimum, with good verbal and written communication skills
• Collaborative, adaptable, and able to manage multiple priorities effectively

NICE TO HAVE (Preferred)

• Experience with LLM-based integrations, Retrieval-Augmented Generation (RAG), or agent orchestration workflows
• Familiarity with MCP (Model Context Protocol) or similar tool/context integrations that connect AI assistants to internal systems
• Exposure to AI-native development practices beyond code completion, such as spec-driven development frameworks, custom prompt or skill libraries, and automation workflows