Junior Java Backend Developer

📍 Lisbon | Hybrid, 3 days/week on-site

🎯 Experience: Around 2 years

🚀 About the Role

We are looking for a Junior Java Backend Developer to join a collaborative engineering team working on the evolution of digital products such as Checkout, MyAccount, and ODR Processing.

You will develop and maintain Java microservices, build and integrate APIs, contribute to automated testing and CI/CD quality gates, and gain exposure to modern Identity & Access Management technologies.

This is an excellent opportunity for an early-career developer who wants to strengthen their backend engineering skills while learning from senior engineers and participating in a structured technical upskilling programme.

🎯 Your Mission

As a Junior Java Backend Developer, you will:

• Develop and maintain Java-based microservices.
• Build and integrate RESTful and GraphQL APIs.
• Write unit and integration tests.
• Contribute to code quality and security practices.
• Support IAM integrations using modern authentication technologies.
• Participate actively in Agile development.
• Continuously expand your technical skills through mentoring and structured training.

💼 Key Responsibilities

Java & Microservices Development

• Develop and maintain backend microservices using Java.
• Implement new functionalities for Checkout, MyAccount, and ODR Processing solutions.
• Work alongside senior engineers to understand technical requirements and solution designs.
• Write clean, maintainable, and testable code.
• Follow established software engineering and coding standards.
• Troubleshoot application issues and contribute to technical improvements.

API Development

• Design and implement RESTful APIs according to established standards.
• Contribute to GraphQL API development and integration.
• Follow OpenAPI documentation standards.
• Implement reliable integrations between backend applications and services.
• Support API testing and troubleshooting.

Testing & Code Quality

• Develop and maintain:
• Unit Tests
• Integration Tests
• Contribute to automated quality gates.
• Work with tools such as:
• SonarQube
• Snyk
• Identify code quality and security issues.
• Support the continuous improvement of test coverage and application reliability.

Identity & Access Management

• Support the integration of authentication and authorization flows.
• Gain hands-on experience with:
• Keycloak
• Okta
• OpenID Connect (OIDC)
• Work with senior engineers to implement secure authentication mechanisms.
• Follow established security guidelines and IAM standards.

Git & Development Workflow

• Work with GitLab-based development workflows.
• Create and contribute to merge requests.
• Follow established pull request and code review processes.
• Apply feedback from senior engineers and technical reviewers.
• Ensure developments meet defined quality and security standards before integration.

Agile Collaboration

• Work within an Agile engineering team.
• Participate actively in:
• Sprint Planning
• Daily Stand-ups
• Sprint Reviews
• Retrospectives
• Collaborate with Developers, QA Engineers, Product stakeholders, and other technical teams.
• Communicate progress, challenges, and dependencies clearly.

Learning & Upskilling

• Participate actively in the structured technical upskilling programme.
• Learn from experienced engineers and subject matter experts.
• Develop deeper knowledge of microservices, APIs, security, testing, and modern backend engineering.
• Apply newly acquired knowledge directly to project activities.
• Build greater technical autonomy over time.

✅ What We're Looking For

Key Requirements

• Approximately 2 years of professional software development experience.
• Professional experience with Java development.
• Good understanding of backend development principles.
• Knowledge of microservices concepts.
• Familiarity with REST APIs.
• Understanding of automated testing principles.
• Experience or familiarity with Git-based development workflows.
• Strong willingness to learn and develop technically.
• Ability to collaborate effectively within a team.
• Portuguese C1.
• English C1.

🛠 Technical Stack

Backend

• Java
• Microservices
• Backend Development

APIs

• REST
• GraphQL
• OpenAPI

Identity & Security

• Keycloak
• Okta
• OpenID Connect
• Authentication & Authorization

Quality & Security

• Unit Testing
• Integration Testing
• SonarQube
• Snyk
• Code Quality
• Security Guidelines

Development & Delivery

• GitLab
• Merge Requests
• Code Reviews
• CI/CD
• Agile

🤝 Soft Skills

• Strong learning mindset and curiosity.
• Good analytical and problem-solving capabilities.
• Team-oriented and collaborative attitude.
• Openness to technical feedback and mentoring.
• Attention to code quality and security.
• Proactive approach to personal and technical development.
• Clear communication in both Portuguese and English.

📍 Working Conditions

• Location: Lisbon
• Work model: Hybrid, 3 days per week in the office
• Experience: Around 2 years
• Languages: Portuguese C1 and English C1

🌟 Why Join?

• Develop modern Java microservices within an enterprise environment.
• Gain practical experience with REST and GraphQL APIs.
• Work with modern IAM technologies such as Keycloak, Okta, and OIDC.
• Strengthen your knowledge of code quality and application security through SonarQube and Snyk.
• Receive guidance from senior engineers.
• Participate in a structured technical upskilling programme.
• Build a strong foundation for progression toward a Mid-Level Backend Engineer position.