Mid-Level Java Backend Engineer

📍 Lisbon | Hybrid, 3 days/week on-site 🎯 Experience: Around 4 years 🚀 About the Role We are looking for a Mid-Level Java Backend Engineer to join an engineering squad responsible for developing and evolving digital products such as Checkout, MyAccount, and ODR Processing. In this role, you will take ownership of features throughout their complete lifecycle, from architecture discussions and implementation to testing, code review, and deployment. You will work with modern backend technologies and integration patterns, including Java microservices, REST and GraphQL APIs, IAM, AWS SQS, and Solace, while contributing to architectural decisions and engineering standards across the squad. 🎯 Your Mission As a Mid-Level Java Backend Engineer, you will: - Design and develop scalable Java microservices. - Take end-to-end ownership of new features. - Build RESTful and GraphQL APIs. - Implement secure authentication and authorization flows. - Develop event-driven integrations and asynchronous processing. - Ensure high standards of code quality, security, and maintainability. - Participate in architecture and technical decisions. - Mentor junior developers and contribute to knowledge sharing. 💼 Key Responsibilities Java & Microservices Development - Design, develop, and maintain scalable Java microservices. - Build new capabilities for Checkout, MyAccount, and ODR Processing products. - Develop robust and maintainable backend components. - Contribute to solution design and technical architecture. - Troubleshoot complex application issues and implement sustainable solutions. - Apply software engineering and clean-code best practices. End-to-End Feature Ownership - Take ownership of features throughout the complete development lifecycle: - Architecture & Technical Design - Development - Automated Testing - Code Review - Deployment - Collaborate with other engineers and stakeholders during solution design. - Identify technical dependencies and risks. - Ensure features are production-ready before release. - Follow delivered functionality through implementation and deployment. API Development - Design and maintain RESTful APIs. - Develop GraphQL APIs and integrations. - Create and maintain complete API specifications based on OpenAPI standards. - Ensure consistent API contracts and integration patterns. - Implement appropriate validation, error handling, and security mechanisms. - Troubleshoot API and integration-related issues. Identity & Access Management - Integrate and configure authentication and authorization solutions using: - Keycloak - Okta - OpenID Connect (OIDC) - Implement Role-Based Access Control (RBAC). - Configure and customize authentication tokens. - Integrate IAM flows with backend services and APIs. - Ensure solutions follow established security and access-control standards. Event-Driven Architecture - Develop asynchronous and event-driven integrations. - Work with: - AWS SQS - Solace - Design reliable messaging flows between applications and services. - Support asynchronous processing and distributed communication patterns. - Troubleshoot messaging and integration issues. - Contribute to resilient and scalable microservices architectures. Testing, Security & Code Quality - Develop and maintain automated tests. - Ensure appropriate unit and integration test coverage. - Contribute to automated pipeline quality gates. - Work with: - SonarQube - Snyk - Identify and remediate code quality and security issues. - Participate actively in code reviews. - Promote secure and maintainable development practices. Git & Delivery - Work within Git-based development workflows. - Participate in merge and pull request processes. - Ensure technical changes are properly reviewed and validated. - Support application deployments. - Contribute to continuous integration and delivery practices. Architecture & Engineering Standards - Participate actively in architectural discussions. - Contribute to backend and integration design decisions. - Help define and improve engineering standards. - Challenge technical solutions when appropriate and propose alternatives. - Promote consistency and reusable development patterns across the squad. Mentoring & Knowledge Sharing - Support and mentor junior engineers. - Provide constructive feedback during code reviews. - Share knowledge around Java, APIs, IAM, messaging, and engineering practices. - Contribute to technical documentation and knowledge-transfer activities. - Help strengthen the team's overall technical capabilities. ✅ What We're Looking For Key Requirements - Around 4 years of professional Software Engineering experience. - Strong professional experience with Java backend development. - Experience developing microservices. - Experience designing and implementing APIs. - Good understanding of distributed application architectures. - Experience with automated testing and code reviews. - Ability to take ownership of features throughout the development lifecycle. - Strong analytical and problem-solving capabilities. - Ability to contribute effectively to technical and architectural discussions. - English C1. - Portuguese C1. 🛠 Technical Stack Backend - Java - Microservices - Backend Services - Distributed Systems APIs - REST - GraphQL - OpenAPI - API Integration IAM & Security - Keycloak - Okta - OpenID Connect (OIDC) - RBAC - Token Customization - Authentication & Authorization Messaging & Event-Driven Architecture - AWS SQS - Solace - Asynchronous Processing - Event-Driven Systems Quality & Security - SonarQube - Snyk - Unit Testing - Integration Testing - Code Reviews - Security Validation Delivery - Git - CI/CD - Deployment - Agile Software Development 🤝 Soft Skills Ownership - Ability to take responsibility for features from initial design to deployment. - Proactive approach to problems and technical risks. - Focus on delivering reliable and maintainable solutions. Technical Thinking - Comfortable participating in architecture discussions. - Ability to understand technical trade-offs and propose practical solutions. - Strong understanding of software engineering principles. Collaboration - Strong team-oriented mindset. - Ability to collaborate effectively with both junior and senior engineers. - Comfortable sharing knowledge and providing technical feedback. Communication - Clear written and verbal communication. - Ability to explain technical decisions and challenges effectively. - Confident communication in Portuguese and English. Continuous Improvement - Interest in improving engineering practices. - Proactive approach to code quality and security. - Willingness to mentor others and continuously expand technical knowledge. 📍 Working Conditions - Location: Lisbon - Work model: Hybrid, 3 days per week in the office 🌟 Why Join? - Take greater ownership of modern Java backend solutions. - Work with microservices and event-driven architectures. - Gain strong exposure to Keycloak, Okta, OIDC, and RBAC. - Develop REST and GraphQL APIs. - Work with AWS SQS and Solace messaging. - Participate directly in architecture and engineering decisions. - Strengthen technical leadership skills through junior mentoring. - Build experience across the entire feature lifecycle, from design to production.